"piece of a barrel," 1750, back-formation from staves (late 14c.), plural of staff (cf. leaves/leaf), possibly from Old English, but not recorded there. The verb (to stave in, past tense stove) is 1590s, originally nautical, on notion of bashing in the staves of a cask and letting out the contents; stave off (1620s) is literally "keep off with a staff," as of dogs.