You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

[Q]: Category: FAMILIAR PHRASES 
Clue: Pool table piece you don't want to be "behind"
[A]: the 8 ball


[Q]: Category: DUMB GUYS' GREATEST INVENTIONS 
Clue: Dumb guys think it's cool they get to slide their own credit card at the store; even cooler? This word for "slide"
[A]: swipe


[Q]: Category: MEN OF MUSIC 
Clue: Horn virtuoso Franz Strauss was consulted by Wagner in devising this hero's horn call
[A]:
siegfried