A metal hook or spear used by fishermen or butchers to lift and maneuver heavy objects: The angler used his gaff to lift the fish from the net into the hold of the boat.
To fix or to set up for cheating: The gambler was known to try to gaff in order to deceive when playing cards.
Social awkwardness or a diplomatic blunder: Aileen was deeply embarrassed by her spoken gaffe
at the garden party.
When Jerome was introduced to Sally, he realized that he had committed an embarrassing gaffe when he didn't pronounce her name correctly.
It would be an unprecedented social gaffe if Emmett were to try to gaff when playing cards; in fact, his opponent might think of using a metal gaff to stop him.