Etymology Dictionary

KEEP,  to regard, have the care of, guard, maintain, hold, preserve.  (L.)   M. E. kepen, pt. t. kepte, pp. kept; Chaucer, C. T. 514 (or 512).—A. S. cépan (weak verb), another form of cýpan, orig. to traffic, sell, hence also to seek after, store up, retain, keep.   See Ælfric's Homilies, i. 412, where we find cýpa, sb. a merchant, chapman; gecýpe, adj. for sale; also:  'gif he dysigra manna herunga cépð on árfæstum weorcum' = if he seek after the praises of men in pious works.   'Goerne ðæs andagan cépton' = they earnestly awaited the appointed day; Ælf. Hom. ii. 172.   'Cépað heora tíman' = they observe (or keep) their times; id. ii. 324.   And see cýpan, cépan, gecýpan, gecépan; Grein, i. 182, 385; also spelt geceápian, as at the last reference.   We find also cýpe as a gloss to Lat. uendo, I sell; Ælfric's Colloquy, in Wright's Vocab. i. 8, l. 8.   β. The A. S. cépan, cýpan, ceápian, are all derivatives from the sb. ceáp, traffic, barter, price; and it has been shewn (s. v. Cheap) that they are not true English words, but of Latin origin.   In fact, keep is a mere doublet of cheapen.   The vowel-changes are perfectly regular; if a word contain eá (as ceáp), the derivative contains é in Early West Saxon, which passes into í, and later into ý; thus the successive forms are cépan, cípan, cýpan (Sweet).   Der. keep, sb., keep-er, keep-er-ship; keep-ing, As You Like It, i. l. 9; also keep-sake, i.e. something which we keep for another's sake, apparently quite a modern word, added by Todd to Johnson's Dict.