To crackle; snap with a sharp, abrupt, and rapidly repeated sound, as salt in fire or during calcination.Specifically To rattle or crackle; use the crepitaculum, as a rattlesnake.In entomology, to eject suddenly from the anus, with a slight noise, a volatile fluid having somewhat the appearance of smoke and a strong pungent odor, as certain bombardier-beetles of the genus Brachinus and its allies.