enterprising (adj.) Look up enterprising at Dictionary.com
"eager to undertake," 1610s, from 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 (12c.), from Old French entretenir "hold together, stick together, support," 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 "amuse" is 1620s. Meaning "to allow (something) to consideration" (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; "that which entertains" is from 1650s; "public performance or display meant to amuse" is from 1727.
enthalpy (n.) Look up enthalpy at Dictionary.com
1927, from Greek enthalpein "to warm in," from en "in" (see en- (2)) + thalpein "to 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. Literal sense is from 1610s. Related: Enthralled; enthralling.
enthrone (v.) Look up enthrone at Dictionary.com
c.1600, from en- (1) + throne. 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," 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" (1650s) under the Puritans; generalized sense of "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 (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 late 18c. Related: Enthusiastically.
enthymeme (n.) Look up enthymeme at Dictionary.com
"a syllogism in which one premise is omitted," 1580s, from Latin enthymema, from Greek enthymema "thought, argument," from enthymesthai "to think, consider," literally "to keep in mind, take to heart," from en "in" (see en- (2)) + thymos "mind" (see fume (n.)).
entice (v.) Look up entice at Dictionary.com
late 13c., intice, from Old French enticier "to stir up (fire), to excite, incite," perhaps from Vulgar Latin *intitiare "set on fire," from Latin in- "in" (see in- (2)) + titio (genitive titionis) "firebrand," of uncertain origin. Meaning "to allure, attract" is from c.1300. Related: Enticed; enticing.
enticement (n.) Look up enticement at Dictionary.com
c.1300, "thing which entices;" 1540s, "action of enticing;" from Old French enticement, from enticier (see entice).
entire (adj.) Look up entire at Dictionary.com
late 14c., from Old French entier "whole, unbroken, intact, complete," from Latin integrum (nominative integer; see integer).
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, 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
late 14c., "to give a title to a chapter, book, etc.," from Anglo-French entitler, Old French entiteler (Modern French intituler), from Late Latin intitulare, 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 long had been used in legal language; 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 meaning "within, inside, inner," from Greek ento-, comb. form of entos "within, inside" (cognate with Latin intus), from PIE *entos, from *en "in" (see in) + 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).
entomologist (n.) Look up entomologist at Dictionary.com
1771; see entomology + -ist.
entomology (n.) Look up entomology at Dictionary.com
1766, from French entomologie (1764), coined from Greek entomon "insect" + -logia "study of" (see -logy). Entomon is neuter of entomos "having a notch or cut (at the waist)," from en "in" (see en- (2)) + temnein "to cut" (see tome).

So called by Aristotle in reference to the segmented division of insect bodies. Compare insect. Related: Entomological. 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]
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). Sense of "attendant persons" first recorded in English by 1860.
entrails (n.) Look up entrails at Dictionary.com
c.1300, from Old French entrailles (12c.), from Late Latin intralia "inward parts, intestines" (8c.), from Latin interanea, neuter plural of interaneus "internal, that which is within," from inter "between, among" (see inter-).
entrain (v.) Look up entrain at Dictionary.com
"to draw along," 1560s, from French entrainer (12c.), from en- "away" (see en- (1)) + trainer "to drag" (see train (n.)). Related: Entrained; entrainment. A word in chemistry; the word meaning "to get on a locomotive train" is a native formation from the 1860s.
entrammel (v.) Look up entrammel at Dictionary.com
1590s, from en- (1) + trammel.
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.
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.
entrant (n.) Look up entrant at Dictionary.com
1630s, of professions, etc.; 1838, of contests; from French entrant, present participle of entrer (see enter).
entrap (v.) Look up entrap at Dictionary.com
1530s, intrappe, from Old French entraper "trap, catch in a trap;" see en- (1) + trap (v.). Related: Entrapped; entrapping.
entrapment (n.) Look up entrapment at Dictionary.com
1590s, from entrap + -ment. Criminal investigation sense first attested 1899.
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," from Latin inter (see inter-).
entreat (v.) Look up entreat at Dictionary.com
mid-14c., "to enter into negotiations;" early 15c., "to treat (someone) in a certain way," also "to plead for (someone)," 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" is first attested c.1500. Related: Entreated; entreating.
entreaty (n.) Look up entreaty at Dictionary.com
mid-15c., "treatment, negotiation;" see entreat + -y (1). Meaning "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. The word had been borrowed in Middle English as entre "act of entering."
entrench (v.) Look up entrench at Dictionary.com
1550s, implied in intrenched, from en- (1) "make, put in" + trench. Figurative use is from 1590s. Related: Entrenched; entrenching.
entrenchment (n.) Look up entrenchment at Dictionary.com
1580s, from entrench + -ment.
entrepot (n.) Look up entrepot at Dictionary.com
"warehouse," 1758, from French entrepôt (16c.), from Latin interpositum "that which is placed between," neuter past participle of interponere (see interposition).
entrepreneur (n.) Look up entrepreneur at Dictionary.com
1828, "manager or promoter of a theatrical production," reborrowing of French entrepreneur "one who undertakes or manages," agent noun from Old French entreprendre "undertake" (see enterprise). The word first crossed the Channel late 15c. but did not stay. Meaning "business manager" is from 1852. Related: Entrepreneurship.
entrepreneurial (adj.) Look up entrepreneurial at Dictionary.com
1922, from entrepreneur + -al (1).
entropy (n.) Look up entropy at Dictionary.com
1868, from German Entropie "measure of the disorder of a system," coined 1865 (on analogy of Energie) by German physicist Rudolph Clausius (1822-1888) from Greek entropia "a turning toward," from en "in" (see en- (2)) + trope "a turning" (see trope). Related: Entropic.
entrust (v.) Look up entrust at Dictionary.com
c.1600, from en- (1) "make, put in" + trust (v.). Related: Entrusted; entrusting.
entry (n.) Look up entry at Dictionary.com
late 13c., "door, gate, that by which a place is entered;" c.1300, "an entering upon; right of entering," from Old French entree "entry, entrance" (12c.), originally fem. past participle of entrer "to enter" (see enter).
entwine (v.) Look up entwine at Dictionary.com
also intwine, 1590s, from en- (1) "make, put in" + twine (n.). Related: Entwined; entwining.
enucleation (n.) Look up enucleation at Dictionary.com
1640s, from verb enucleate (1540s), from Latin enucleatus "pure, clean," past participle of enucleare "to lay open, explain in detail," literally "to remove the kernel of" (see ex- + nucleus). Mostly figurative in Latin (the notion is of getting at the "core" of some matter); until mid-19c. advances in science and medicine, usually figurative in English.
enumerate (v.) Look up enumerate at Dictionary.com
1610s, from or modeled on Latin enumeratus, past participle of enumerare (see enumeration). Middle English had annumerate (early 15c.). Related: Enumerated; enumerating.
enumeration (n.) Look up enumeration at Dictionary.com
1550s, from Middle French énumération, from Latin enumerationem (nominative enumeratio) "a counting up," noun of action from past participle stem of enumerare "to reckon up, count over, enumerate," from ex- "from" (see ex-) + numerare "to count, number," from numerus "number" (see number (n.)).