Merriam-Webster Collegiate Dictionary - cleave

 I. intransitive verb  (~d or clove; also clave; ~d; cleaving)  Etymology: Middle English clevien, from Old English clifian; akin to Old High German kleben to stick  Date: before 12th century to adhere firmly and closely or loyally and unwaveringly  Synonyms: see stick  II. verb  (~d; also cleft or clove; ~d; also cleft or cloven; cleaving)  Etymology: Middle English cleven, from Old English cleofan; akin to Old Norse kljufa to split, Latin glubere to peel, Greek glyphein to carve  Date: before 12th century  transitive verb  1. to divide by or as if by a cutting blow ; split  2. to separate into distinct parts and especially into groups having divergent views  3. to subject to chemical cleavage a protein ~d by an enzyme  intransitive verb  1. to split especially along the grain  2. to penetrate or pass through something by or as if by cutting  Synonyms: see tear