Definition from Wiktionary, the free dictionary
Alternative forms 
- A sheet of paper containing notes used to assist (with or without permission) on a test.
- (idiomatic) Any summary or quick reference used as a shortcut or reminder, a crib sheet.
- If you have trouble remembering all the trigonometric identities, the book has a cheat sheet in back that lists them.
A sheet of paper used to assist on a test