"divided, split," Old English clofen, past-participle adjective from cleave (v.1). Sometimes shortened to clove, hence clove-hitch (1769), etc. Cloven hoof, characteristic of ruminant quadrupeds (and ascribed in mythology to Pan and the Devil) is from c. 1200.
cloudscape
cloudy
clough
clout
clove
cloven
clover
clover-leaf
Clovis
clowder
clown