(informal) To open up one's books, especially in order to study.

present participle of crack a book

Used other than figuratively or idiomatically: see hard, nut, crack. / (idiomatic) A problem that is challenging to solve.

plural of hard nut to crack

(slang) An intergluteal cleft visible due to low-riding pants, especially when one is bending over.

Alternative form of hard nut to crack

(mildly vulgar, derogatory) Less vulgar synonym of full of shit.

A crane, consisting of a balanced beam erected on top of a tall metal (normally self-erecting) tower, used in the construction of tall buildings

Alternative spelling of safecracker

(informal) Suggesting traditional handicraft.