cleft (adj.)

late 14c., past-participle adjective from cleave (v.1)). Cleft palate attested from 1828.

cleft (n.)

1570s, alteration (by influence of cleft, new weak past participle of cleave (v.1)), of Middle English clift (early 14c.), from Old English geclyft (adj.) "split, cloven," from Proto-Germanic *kluftis (source also of Old High German and German kluft, Danish kløft "cleft"), from PIE *gleubh- (see glyph). In Middle English anatomy, it meant "the parting of the thighs" (early 14c.).