[cleft] n [ME clift, fr. OE geclyft; akin to OE cleofan to cleave] (14c) 1: a space or opening made by or as if by splitting: fissure
2: a usu. V-shaped indented formation: a hollow between ridges or protuberances "the anal ~ of the human body"
[2]cleft adj [ME, fr. pp. of cleven] (14c): partially split or divided; specif: divided about halfway to the midrib "a ~ leaf"