1788, "that which results from something," originally Scottish, from the verbal phrase; see out (adv.) + come (v.). Popularized in English by Carlyle (c. 1830s). It was used in Middle English in sense of "an emergence, act or fact of coming out" (c. 1200), and the gerund, outcoming, was used as "an issue, a result." Old English had utancumen (n.) "stranger, foreigner."
Middle English couth "known, well-known; usual, customary," from Old English cuðe "known," past participle of cunnan "to know," less commonly "to have power to, to be able" (see can (v.1)).
As a past participle it died out 16c. with the emergence of could, but the old word was reborn 1896, with a new sense of "cultured, refined," as a back-formation from uncouth (q.v.). The Old English word forms the first element in the masc. proper name Cuthbert, which literally means "famous-bright."
Old English apa (fem. ape) "an ape, a monkey," from Proto-Germanic *apan (source also of Old Saxon apo, Old Norse api, Dutch aap, German affe), probably a borrowed word, perhaps from Celtic (compare Old Irish apa, Welsh epa) or Slavic (compare Old Bohemian op, Slovak opitza), and the whole group probably is ultimately from an Eastern or non-Indo-European language.
The common word until the emergence of monkey in 16c. More technically, in zoology, "a simian; tail-less, man-like monkey" 1690s. The only native apes in Europe are the Barbary apes of Gibraltar, intelligent and docile, and these were the showman's apes of the Middle Ages. Apes were noted in medieval times for mimicry of human action, hence, perhaps, the other figurative use of the word, to mean "a fool" (c. 1300).
To go ape "go crazy" is by 1953 (unsanitized or emphatic go apeshit is by 1954), American English; early attestations suggest armed forces slang. To lead apes in hell (1570s) was the fancied fate of one who died an old maid. Middle English plural was occasionally apen. Middle English also had ape-ware "deceptions, tricks."