enter (v.) Look up enter at Dictionary.com
late 13c. entren, "enter into a place or a situation; join a group or society" (trans.); early 14c., "make one's entrance" (intrans.), from Old French entrer "enter, go in; enter upon, assume; initiate," from Latin intrare "to go into, enter" (source of Spanish entrar, Italian entrare), from intra "within," related to inter (prep., adj.) "among, between" (see inter-). Transitive and intransitive in Latin; in French intransitive only. From c. 1300 in English as "join or engage in: (an activity);" late 14c. as "penetrate," also "have sexual intercourse" (with a woman);" also "make an entry in a record or list," also "assume the duties" (of office, etc.). Related: Entered; entering.
enteric (adj.) Look up enteric at Dictionary.com
"pertaining to the intestines," 1822, from Latinized form of Greek enterikos "intestinal," first used in this sense by Aristotle, from entera (plural; singular enteron) "intestines," from PIE *enter-, comparative of *en "in" (see inter-).
enteritis (n.) Look up enteritis at Dictionary.com
"acute inflammation of the bowels," 1808, medical Latin, coined c. 1750 by French pathologist François-Boissier de la Croix de Sauvages (1706-1767), from enteron "intestine" (see enteric) + -itis "inflammation."
entero- Look up entero- at Dictionary.com
before vowels enter-, word-forming element meaning "intestine," from comb. form of Greek enteron "an intestine, piece of gut" (see enteric).
enterovirus (n.) Look up enterovirus at Dictionary.com
1957; see entero- + virus.
enterprise (n.) Look up enterprise at Dictionary.com
early 15c., "an undertaking," formerly also enterprize, from Old French enterprise "an undertaking," noun use of fem. past participle of entreprendre "undertake, take in hand" (12c.), from entre- "between" (see entre-) + prendre "to take," contraction of prehendere (see prehensile). Abstract sense of "adventurous disposition, readiness to undertake challenges, spirit of daring" is from late 15c.
enterprising (adj.) Look up enterprising at Dictionary.com
"eager to undertake, prompt to attempt," 1610s, present participle adjective from the verb enterprise (late 15c.), from the noun enterprise. Until mid-19c. (at least in Britain) mostly in a bad sense: "scheming, ambitious, foolhardy." Earlier (1560s) as a verbal noun meaning "action of undertaking."
entertain (v.) Look up entertain at Dictionary.com
late 15c., "to keep up, maintain, to keep (someone) in a certain frame of mind," from Middle French entretenir, from Old French entretenir "hold together, stick together, support" (12c.), from entre- "among" (from Latin inter; see inter-) + tenir "to hold" (from Latin tenere; see tenet).

Sense of "have a guest" is late 15c.; that of "gratify, amuse" is 1620s. Meaning "to allow (something) to consideration, take into the mind" (of opinions, notions, etc.) is 1610s. Related: Entertained; entertaining.
entertainer (n.) Look up entertainer at Dictionary.com
"public performer," 1530s, agent noun from entertain.
entertainment (n.) Look up entertainment at Dictionary.com
1530s, "provision for support of a retainer; manner of social behavior," now obsolete, along with other 16c. senses; from entertain + -ment. Meaning "the amusement of someone" is from 1610s; sense of "that which entertains" is from 1650s; that of "public performance or display meant to amuse" is from 1727.
enthalpy (n.) Look up enthalpy at Dictionary.com
1927 in physics, from Greek enthalpein "to warm in," from en "in" (see en- (2)) + thalpein "to heat," from thalpos "warmth, heat," especially "summer heat."
enthrall (v.) Look up enthrall at Dictionary.com
also enthral "to hold in mental or moral bondage," 1570s, from en- (1) "make, put in" + thrall (n.). Literal sense (1610s) is rare in English. Related: Enthralled; enthralling.
enthrone (v.) Look up enthrone at Dictionary.com
c. 1600, from en- (1) + throne (n.). Replacing enthronize (late 14c.), from Old French introniser (13c.), from Late Latin inthronizare, from Greek enthronizein. Also simply throne (v.), late 14c., from the noun in English. Related: Enthroned; enthroning.
enthuse (v.) Look up enthuse at Dictionary.com
1827, American English, back-formation from enthusiasm. Originally often humorous or with affected ignorance. Related: enthused; enthusing.
enthusiasm (n.) Look up enthusiasm at Dictionary.com
c. 1600, from Middle French enthousiasme (16c.) and directly from Late Latin enthusiasmus, from Greek enthousiasmos "divine inspiration, enthusiasm (produced by certain kinds of music, etc.)," from enthousiazein "be inspired or possessed by a god, be rapt, be in ecstasy," from entheos "divinely inspired, possessed by a god," from en "in" (see en- (2)) + theos "god" (see theo-). Acquired a derogatory sense of "excessive religious emotion through the conceit of special revelation from God" (1650s) under the Puritans; generalized meaning "fervor, zeal" (the main modern sense) is first recorded 1716.
enthusiast (n.) Look up enthusiast at Dictionary.com
1560s, pejorative, "one who believes himself possessed of divine revelations or special communication from God," from Greek enthousiastes "a person inspired," from enthousiazein (see enthusiasm). General sense (not always entirely pejorative) is from mid-18c.
enthusiastic (adj.) Look up enthusiastic at Dictionary.com
c. 1600, "pertaining to possession by a deity," from Greek enthousiastikos "inspired," from enthousiazein "be possessed or inspired by a god" (see enthusiasm). Meaning "pertaining to irrational delusion in religion" is from 1690s. The main modern sense, in reference to feelings or persons, "intensely eager, rapturous," is from 1786. Related: Enthusiastically.
enthymeme (n.) Look up enthymeme at Dictionary.com
"a syllogism in which one premise is omitted," in Aristotle, "an inference from likelihoods and signs," 1580s, from Latin enthymema, from Greek enthymema "thought, argument, piece of reasoning," from enthymesthai "to think, consider," literally "to keep in mind, take to heart," from en "in" (see en- (2)) + thymos "mind" (see fume (n.)). Related: Enthymematic.
entice (v.) Look up entice at Dictionary.com
late 13c., intice, from Old French enticier "to stir up (fire), to excite, incite," which is of uncertain origin, perhaps from Vulgar Latin *intitiare "set on fire," from Latin in- "in" (see in- (2)) + titio (genitive titionis) "firebrand," which is of uncertain origin. Meaning "to allure, attract" is from c. 1300. Related: Enticed; enticing; enticingly.
enticement (n.) Look up enticement at Dictionary.com
c. 1300, "thing which entices," from Old French enticement "incitement, instigation, suggestion," from enticier (see entice). From 1540s as "action of enticing."
entire (adj.) Look up entire at Dictionary.com
late 14c., from Old French entier "whole, unbroken, intact, complete," from Latin integrum "completeness" (nominative integer; see integer). Related: Entireness.
entirely (adv.) Look up entirely at Dictionary.com
mid-14c., from entire + -ly (2).
entirety (n.) Look up entirety at Dictionary.com
also entierty, mid-14c., enterete, intierty, from Anglo-French entiertie, Old French entiereté "totality, entirety; integrity, purity," from Latin integritatem (nominative integritas) "completeness, soundness, integrity," from integer (see integer).
entitle (v.) Look up entitle at Dictionary.com
also intitle, late 14c., "to give a title to a chapter, book, etc.," from Anglo-French entitler, Old French entiteler "entitle, call" (Modern French intituler), from Late Latin intitulare "give a title or name to," from in- "in" (see in- (2)) + titulus "title" (see title (n.)).

Meaning "to bestow (on a person) a rank or office" is mid-15c. Sense of "to give (someone) 'title' to an estate or property," hence to give that person a claim to possession or privilege, is mid-15c.; this now is used mostly in reference to circumstances and actions. Related: Entitled; entitling.
entitlement (n.) Look up entitlement at Dictionary.com
1823, perhaps in some senses from French entitlement, which was in Old French as "tit;e (of a book), inscription," and later was used in legal language; but also in part a native formation from entitle + -ment. Entitlement culture attested by 1994 (culture of entitlement is from 1989).
entity (n.) Look up entity at Dictionary.com
1590s, from Late Latin entitatem (nominative entitas), from ens (genitive entis) "a thing," proposed by Caesar as present participle of esse "be" (see is), to render Greek philosophical term to on "that which is" (from neuter of present participle of einai "to be;" see essence). Originally abstract; concrete sense in English is from 1620s.
ento- Look up ento- at Dictionary.com
word-forming element used chiefly in biology and meaning "within, inside, inner," from Greek ento-, comb. form of entos (adv., prep.) "within, inside," as a noun, "inner parts" (cognate with Latin intus), from PIE *entos-, extended form of root *en "in" (see in), with adverbial suffix *-tos, denoting origin.
entomb (v.) Look up entomb at Dictionary.com
1570s, from Old French entomber "place in a tomb," from en- "in" (see en- (1)) + tombe "tomb" (see tomb). Related: Entombed; entombing. The earlier verb was simply tomb (c. 1300).
entombment (n.) Look up entombment at Dictionary.com
1660s, from entomb + -ment.
entomolite (n.) Look up entomolite at Dictionary.com
"fossilized insect," 1813, from entomo-, from Greek entomon "insect" (see entomology) + -lite "stone." Late 18c. in French and German.
entomologist (n.) Look up entomologist at Dictionary.com
1771; see entomology + -ist.
entomology (n.) Look up entomology at Dictionary.com
1764, from French entomologie (1764), coined from -logie "study of" (see -logy) + Greek entomon "insect," neuter of entomos "cut in pieces, cut up," in this case "having a notch or cut (at the waist)," from en "in" (see en- (2)) + temnein "to cut" (see tome).

Insects were so called by Aristotle in reference to the segmented division of their bodies. Compare insect, which is from a Latin loan-translation of the Greek word. Related: Entomological; entomologically. Hybrid insectology (1766, from French insectologie, 1744) is not much used.
I have given the name insectology to that part of natural history which has insects for its object; that of entomology ... would undoubtedly have been more suitable ... but its barbarous sound terryfy'd me. [Charles Bonnet's English translation of his "Contemplation de la nature," 1766]
entomophagous (adj.) Look up entomophagous at Dictionary.com
"insectivorous," 1800, from entomo-, from Greek entomon "insect" (see entomology) + -phagous.
entoparasite (n.) Look up entoparasite at Dictionary.com
1847; see ento- + parasite. Perhaps from German or French.
entourage (n.) Look up entourage at Dictionary.com
1832, "surroundings, environment," picked up by De Quincey from French entourage, from Middle French entourer "to surround" (16c.), from Old French entour "that which surrounds" (10c.), from en- "in" (see en- (1)) + tour "a circuit" (see tour). Specific sense of "attendant persons, persons among whom as followers or companions one is accustomed to move" recorded in English by 1860.
entrails (n.) Look up entrails at Dictionary.com
"internal parts of animal bodies," c. 1300, from Old French entrailles (12c.), from Late Latin intralia "inward parts, intestines" (8c.), from altered form of Latin interanea, noun use of neuter plural of interaneus "internal, that which is within," from inter "between, among" (see inter-). Latin interanea yielded Late Latin intrania, hence Italian entrango, Spanish entrañas, Old French entraigne; the alternative form that led to the Modern English word evidently is from influence of the Latin neuter plural (collective) adjective suffix -alia (French -aille).
entrain (v.1) Look up entrain at Dictionary.com
"to draw along," 1560s, a term in chemistry, from French entrainer (12c.), from en- "away" (see en- (1)) + trainer "to drag" (see train (n.)). Related: Entrained; entrainment.
entrain (v.2) Look up entrain at Dictionary.com
"get on board a locomotive train," 1860s, from en- (1) "in, into" + train (n.). Related: Entrained.
entrammel (v.) Look up entrammel at Dictionary.com
"to entangle," 1590s, from en- (1) "in" + trammel (n.).
entrance (n.) Look up entrance at Dictionary.com
1520s, "act of entering," from Middle French entrance, from entrer (see enter). Sense of "door, gate" first recorded in English 1530s. Meaning "a coming of an actor upon the stage" is from c. 1600.
entrance (v.) Look up entrance at Dictionary.com
"to throw into a trance," 1590s, from en- (1) "put in" + trance (n.). Meaning "to delight" also is 1590s. Related: Entranced; entrancing; entrancement.
entrant (n.) Look up entrant at Dictionary.com
1630s, "one who enters, a beginner" (of professions, etc.); from French entrant, present participle of entrer (see enter). From 1838 with reference to one who enters a contest. As an adjective from 1630s.
entrap (v.) Look up entrap at Dictionary.com
"to catch, as in a trap," 1530s, intrappe, from Old French entraper "trap, catch in a trap;" see en- (1) + trap (n.). Related: Entrapped; entrapping.
entrapment (n.) Look up entrapment at Dictionary.com
1590s, from entrap + -ment. Criminal investigation sense attested by 1896.
entre nous Look up entre nous at Dictionary.com
"in private," French, literally "between ourselves."
entre- Look up entre- at Dictionary.com
in words from French, corresponds to English enter-, which is itself from French entre "between, among" (11c.), from Latin inter (see inter-).
entreat (v.) Look up entreat at Dictionary.com
c. 1400, "to enter into negotiations," especially "discuss or arrange peace terms;" also "to treat (someone) in a certain way," from Anglo-French entretier, Old French entraiter "to treat," from en- "make" (see en- (1)) + traiter "to treat" (see treat (v.)). Meaning "to beseech, implore, plead with (someone)" is from early 15c.; meaning "to plead for (someone)" is from mid-15c. Related: Entreated; entreating.
entreaty (n.) Look up entreaty at Dictionary.com
mid-15c., "treatment; negotiation;" see entreat + -y (1). Meaning "urgent solicitation, earnest request" is from 1570s. Related: Entreaties.
entree (n.) Look up entree at Dictionary.com
1724, "opening piece of an opera or ballet," from French entrée, from Old French entree (see entry). Cookery sense is from 1759; originally the dish which was introductory to the main course. Meaning "entry, freedom of access" is from 1762. The word had been borrowed in Middle English as entre "act of entering."
entrench (v.) Look up entrench at Dictionary.com
also intrench, 1550s, implied in intrenched, from en- (1) "make, put in" + trench (n.). Figurative use is from 1590s. Related: Entrenched; entrenching.