*keuə-, Proto-Indo-European root meaning "to swell," also "vault, hole."

It forms all or part of: accumulate; accumulation; cave; cavern; cavity; coeliac; church; codeine; coelacanth; coeliac; coelomate; concave; cumulate; cumulative; cumulus; enceinte; excavate; kirk; kymatology; Kyrie eleison.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit svayati "swells up, is strong;" Greek kyein "to swell," koilos "hollow, hollowed out, spacious, deep;" Latin cumulus "a heap, pile, mass, surplus;" Lithuanian šaunas "firm, solid, fit, capable;" Middle Irish cua "hollow;" Armenian soyl "cavity."

1869, "act or fact of flowing out, a flowing out or forth;" 1875, "that which flows out," from out- + flow (n.).

also out-bid, 1580s, "offer a higher price than," from out- + bid (v.). Related: Out-bidding; out-bidden. Middle English had utbidden "to summon (warriors), muster (an army," c. 1300, on the notion of "call out."

"to draw out, withdraw, take or get out, pull out or remove from a fixed position, literally or figuratively," late 15c., from Latin extractus, past participle of extrahere "draw out," from ex "out, out of" (see ex-) + trahere "to draw" (see tract (n.1)). Related: Extracted; extracting.

of things, "to thrust out; force, press, or crowd out; expel," 1560s, from Latin extrudere "to thrust out, drive away," from ex "out, out of" (see ex-) + trudere "to thrust, push," from PIE *treud- "to press, push, squeeze" (see threat). Related: Extruded; extruding.

"act of shutting out; non-inclusion," c. 1400, exclusioun, from Latin exclusionem (nominative exclusio) "a shutting out," noun of action from past-participle stem of excludere "keep out, shut out," from ex "out" (see ex-) + claudere "to close, shut" (see close (v.)).

also out-dated, "grown obsolete," 1590s, from out- + past participle of date (v.1). Out-of-date is attested from 1610s. The verb, out-date "make obsolete" is by 1640s, perhaps 1590s.

mid-15c., from Latin eiectus "thrown out," past participle of eicere "throw out, cast out, thrust out; drive into exile, expel, drive away," from ex "out" (see ex-) + -icere, combining form of iacere "to throw" (from PIE root *ye- "to throw, impel"). Related: Ejected; ejecting. Ejecta "matter thrown out by a volcano" is from 1851.

c. 1600, "that which flows out;" 1620s, "act of flowing out," from Late Latin effluentia, from Latin effluentem (nominative effluens) "flowing out," present participle of effluere "to flow out," from assimilated form of ex "out" (see ex-) + fluere "to flow" (see fluent). Related: Effluency.

"put out, extinguish," especially in outen the light, 1916, American English dialectal; see out (adv.) + -en (1). An idiom in Pennsylvania German. In English, out (v.) "to put out" is attested from c. 1500.