*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."
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.