n. A crackling noise, resembling a succession of minute explosions, such as the crackling of some salts in calcination, or the noise made in the friction of fractured bones when moved in certain directions; also, in pathology, the grating sensation felt by the hand when applied to fractured bones under movement; crepitus.n. Specifically In pathol., certain sounds detected in the lungs by auscultation; the peculiar crackling sound which characterizes pneumonia; crepitant rales.n. The action of a crepitaculum, as of that of a rattlesnake; stridulation.n. In entomology, the act of ejecting a pungent fluid from the anus, with a slight noise. See crepitate, 3.n. The peculiar crackling sensation felt on palpation of emphysematous tissues.