excellent

he is in cracking form to win this race

a cracking good story

break or cause to break without a complete separation of the parts

the ice all over the bog had cracked

take care not to crack the glass

make or cause to make a sudden sharp or explosive sound

a shot cracked across the ridge

he cracked his whip and galloped away

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