The formation of cracks on a surface.
The thermal decomposition of a substance, especially that of crude petroleum in order to produce petrol / gasoline.
The production of a crack sound.
Very, usually associated with praise.
Enjoyable.
That cracks; that produces a sharp sound as of something splitting or breaking.
Great.
A very thin fissure.
A fishing line made from hair.
The line along one's forehead where hair starts growing.
A very thin line in writing, drawing, or typography.
very thin, as thin as a hair