a sudden sharp noise; "the crack of a whip"; "he heard the cracking of the ice"; "he can hear the snap of a twig";
the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process);
very good; "he did a bully job"; "a neat sports car"; "had a great time at the party"; "you look simply smashing";
