1
general::
1. On credit, as in He tried to hire a detective on the cuff. It is sometimes put as put on the cuff, meaning "extend credit to," as in They asked to be put on the cuff until they got their monthly check. This usage prob ably alludes to the practice of recording bar tabs on the bartender's cuff. Also see OFF THE CUFF. [Slang; 1920s] 2. Free of charge, as in We hope these drinks are on the cuff. [Slang; 1920s] Also see ON THE HOUSE.
American Heritage Idioms