☆ the process of breaking down heavier hydrocarbons by heat and pressure or by catalysts into lighter hydrocarbons of lower molecular weight, as in producing gasoline from petroleum
See cracking in American Heritage Dictionary 4
noun
Thermal decomposition, sometimes with catalysis, of a complex substance, especially the breaking of petroleum molecules into shorter molecules to extract low-boiling fractions such as gasoline.
adjective
Excellent; great: had a cracking time at the dance.