ITYM
gaffe noun:
an unintentional act or remark causing embarrassment to its originator; a blunder.
Whereas...
gaff - noun:
1. a stick with a hook or barbed spear, for landing large fish.
2. [sailing] a spar to which the head of a fore-and-aft sail is bent ("a gaff-rigged cutter").
3. [British slang, archaic] a person's home, esp a flat (Also called: penny-gaff a cheap or low-class place of entertainment, especially a cheap theatre or music hall in Victorian England).
verb: seize or impale with a gaff.
As you were...