The cuffs of a shirt or dress are the parts at the ends of the sleeves, which are thicker than the rest of the sleeve.

The cuffs on a pair of pants or trousers are the parts at the ends of the legs, which are folded up.

If you cuff someone, you hit them quickly and lightly with your hand, usually on their head or their ear.

If the police cuff someone, they put handcuffs on them.

An off-the-cuff remark is made without being prepared or thought about in advance.