[noun] a sudden sharp noise; "the crack of a whip"; "he heard the cracking of the ice"; "he can hear the snap of a twig" Synonyms:crack, snap
[noun] the act of cracking something Synonyms:fracture, crack
[noun] the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)
