clatter (v.) Look up clatter at Dictionary.com
late Old English clatrung, probably from Old English *clatrian, of imitative origin. Cf. Middle Dutch klateren, East Frisian klatern, dialectal German klattern. The noun is attested from mid-14c.
Clatterer or clatterfart, which wyl disclose anye light secreate. [Richard Huloet, "Abecedarium Anglo-Latinum," 1552.]