enough (adj.) Look up enough at Dictionary.com
c. 1300, from Old English genog "sufficient in quantity or number," from Proto-Germanic compound *ganoga- "sufficient" (cognates: Old Saxon ginog, Old Frisian enoch, Dutch genoeg, Old High German ginuog, German genug, Old Norse gnogr, Gothic ganohs).

First element is Old English ge- "with, together" (also a participial, collective, intensive, or perfective prefix), making this word the most prominent surviving example of the Old English prefix, the equivalent of Latin com- and Modern German ge- (from PIE *kom- "beside, near, by, with;" see com-). Second element is from PIE *nok-, from root *nek- (2) "to reach, attain" (cognates: Sanskrit asnoti "reaches," Hittite ninikzi "lifts, raises," Lithuanian nešti "to bear, carry," Latin nancisci "to obtain").

As an adverb, "sufficiently for the purpose," in Old English; meaning "moderately, fairly, tolerably" (good enough) was in Middle English. Understated sense, as in have had enough "have had too much" was in Old English (which relied heavily on double negatives and understatement). As a noun in Old English, "a quantity or number sufficient for the purpose." As an interjection, "that is enough," from c. 1600. Colloquial 'nough said is attested from 1839.
enow (adj., n.) Look up enow at Dictionary.com
Old English genoge (plural adjective), from genog (see enough). By Johnson, regarded as the plural of enough.
enquire (v.) Look up enquire at Dictionary.com
alternative form of inquire, according to OED mainly used in sense of "to ask a question." Related: enquired; enquiring.
enquiry (n.) Look up enquiry at Dictionary.com
alternative spelling of inquiry. Also see enquire. Related: Enquiries.
enrage (v.) Look up enrage at Dictionary.com
late 14c., "make furious or mad" (implied in enraged), from Old French enragier "go wild, go mad, lose one's senses," from en- "make, put in" (see en- (1)) + rage "rabies, rage" (see rage (n.)). Related: Enraging. Intransitive only in Old French; but the transitive sense is oldest and predominant in English.
enrapt (adj.) Look up enrapt at Dictionary.com
c. 1600, "carried away by (prophetic) ecstasy," from en- "make, put in" (see en- (1)) + rapt.
enrapture (v.) Look up enrapture at Dictionary.com
1740, from en- (1) "put in" + rapture (n.). Related: Enraptured.
enrich (v.) Look up enrich at Dictionary.com
late 14c., "to make wealthy," from Old French enrichir "enrich, enlarge," from en- "make, put in" (see en- (1)) + riche "rich" (see rich). Figurative sense "supply with abundance of something desirable" is from 1590s. Meaning "to fertilize" is from c. 1600. Scientific sense of "to increase the abundance of a particular isotope in some material" is first attested 1945. Related: Enriched; enriching.
enrichment (n.) Look up enrichment at Dictionary.com
1620s, from enrich + -ment.
enrobe (v.) Look up enrobe at Dictionary.com
1590s, from en- (1) "in" + robe (n.). Related: Enrobed; enrobing.
enrol (v.) Look up enrol at Dictionary.com
alternative spelling of enroll. Related: Enroled; enroling.
enroll (v.) Look up enroll at Dictionary.com
mid-14c. (transitive), from Old French enroller "record in a register, write in a roll" (13c., Modern French enrôler), from en- "make, put in" (see en- (1)) + rolle (see roll (n.)). Related: Enrolled; enrolling.
enrollment (n.) Look up enrollment at Dictionary.com
also enrolment, mid-15c., "act of enrolling," from Anglo-French enrollement, from Middle French enrollement, from Old French enroller "record in a register" (see enroll). Meaning "total number enrolled" is from 1859, American English.
ensample (n.) Look up ensample at Dictionary.com
"precedent to be followed, illustrative instance; a pattern, model," c. 1300, variant of asaumple, from Old French essample "example" (see example). The survival of this variant form is due to its use in New Testament in KJV (1 Pet. v.3).
ensconce (v.) Look up ensconce at Dictionary.com
1580s, "to cover with a fort," from en- (1) "make, put in" + sconce "small fortification, shelter," perhaps via French, probably from Dutch schans "earthwork" (compare Middle High German schanze "bundle of sticks"), which is of uncertain origin. Hence, "to fix firmly, settle" (1590s). Related: Ensconced.
ensemble (n.) Look up ensemble at Dictionary.com
1703, "union of parts, parts of a thing taken together," from French ensemblée "all the parts of a thing considered together," from Late Latin insimul "at the same time," from in- intensive prefix + simul "at the same time," related to similis (see similar). Musical sense of "union of all parts in a performance" in English first attested 1844. Of women's dress and accessories, from 1927. Earlier in English as an adverb (mid-15c.), "together, at the same time."
enshrine (v.) Look up enshrine at Dictionary.com
1580s, from en- (1) "make, put in" + shrine (n.). Related: Enshrined; enshrining.
enshroud (v.) Look up enshroud at Dictionary.com
1580s, from en- (1) "make, put in" + shroud (n.). Related: Enshrouded; enshrouding.
ensign (n.) Look up ensign at Dictionary.com
early 15c., "a token, sign, symbol; badge of office, mark or insignia of authority or rank;" also "battle flag, flag or banner of a ship or troop of soldiers," via Scottish, from Old French enseigne (12c.) "mark, symbol, signal; flag, standard, pennant," from Latin insignia (plural); see insignia, which is a doublet of this word. As the word for the soldier who carries the flag, 1510s. U.S. Navy sense of "commissioned officer of the lowest rank" is from 1862. French navy had rank of enseigne de vaisseau since at least early 18c. Until 1871 one of the lowest grades of commissioned officers in a British army infantry regiment, also a rank in the American Revolutionary army.
ensilage (n.) Look up ensilage at Dictionary.com
1879, from French ensilage, from ensiler "put in a silo," from Spanish ensilar (see silo).
enslave (v.) Look up enslave at Dictionary.com
1640s, from en- (1) "make, make into" + slave (n.). Related: Enslaved; enslaving.
enslavement (n.) Look up enslavement at Dictionary.com
1690s, from enslave + -ment.
ensnare (v.) Look up ensnare at Dictionary.com
1570s, from en- (1) "make, put in" + snare (n.). Related: Ensnared; ensnaring.
ensorcell (v.) Look up ensorcell at Dictionary.com
also ensorcel, "to bewitch," 1540s, from French ensorceller, from Old French ensorceler, dissimilated from ensorcerer from en- (see en- (1)) + verb from sorcier "sorcerer, wizard" (see sorcery). Related: Ensorcelled; ensorceled.
ensue (v.) Look up ensue at Dictionary.com
c. 1400, "seek after, pursue; follow (a path)," from Old French ensu-, past participle stem of ensivre "follow close upon, come afterward," from Late Latin insequere, from Latin insequi "to pursue, follow, follow after; come next," from in- "upon" (see in- (2)) + sequi "follow" (see sequel). Early 15c. as "follow (as a consequence), to result;" mid-15c. as "to follow" in time or space, "to come or appear next, be subsequent to, happen subsequently." Related: Ensued; ensues; ensuing.
ensure (v.) Look up ensure at Dictionary.com
late 14c., from Anglo-French enseurer, from en- "make" (see en- (1)) + Old French seur "sure" (see sure); probably influenced by Old French asseurer "assure." Compare insure. Related: Ensured; ensures; ensuring.
entablature (n.) Look up entablature at Dictionary.com
1610s, in architecture, nativization of Italian intavolatura; see en- (1) + tablature.
entail (v.) Look up entail at Dictionary.com
mid-14c., "convert (an estate) into 'fee tail' (feudum talliatum)," from en- (1) "make" + taile "legal limitation," especially of inheritance, ruling who succeeds in ownership and preventing the property from being sold off, from Anglo-French taile, Old French taillie, past participle of taillier "allot, cut to shape," from Late Latin taliare "to split" (see tailor). Sense of "have consequences" is 1829, via the notion of "inseparable connection." Related: Entailed; entailling; entailment.
entangle (v.) Look up entangle at Dictionary.com
early 15c., from en- (1) + tangle (n.). Related: Entangled; entangling.
entanglement (n.) Look up entanglement at Dictionary.com
1630s, "that which entangles," from entangle + -ment. From 1680s as "act of entangling." Foreign entanglements does not appear as such in Washington's Farewell Address (1796), though he warns against them. The phrase is found in William Coxe's 1798 memoirs of Sir Robert Walpole.
entelechy (n.) Look up entelechy at Dictionary.com
c. 1600, from Latinized form of Greek entelekheia "actuality," from en "in" (see en- (2)) + telei, dative of telos "perfection" (see tele-) + ekhein "to have" (see scheme (n.)). In Aristotle, "the condition in which a potentiality has become an actuality."
entente (n.) Look up entente at Dictionary.com
"an understanding," 1854, from French éntente "an understanding," from Old French entente "intent, intention; attention; aim, goal" (12c.), noun use of fem. past participle of entendre "to direct one's attention" (see intent). Political sense arose in 19c. from entente cordiale (1844); the best-known example was that between England and France (1904), to which Russia was added in 1908.
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.