(of a person) lacking reason; completely irrational
you must think my family are cracked
find a solution to; decipher or interpret
the code will help you crack the messages
tell (a joke)
he cracked jokes which she didn't find very funny
decompose (hydrocarbons) by heat and pressure with or without a catalyst to produce lighter hydrocarbons, especially in oil refining
catalytic cracking increases gasoline yields