Crap

·add. ·noun In the game of craps, a first throw of the dice in which the total is two, three, or twelve, in which case the caster loses.

crap
1) darnel. Suss. In the north it is sometimes used for money. 2) sometimes used for buck-wheat. ...

A glossary of provincial and local words used in England by Francis Grose
Crap shooting
·add. ·- ·same·as <<Craps>>. ...

Webster's Dictionary of the English Language