Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

[Q]: Category: physical activity 
Words: drop, fall, leaves, bend, exercise
[A]: leaves


[Q]: Category: poker 
Words: fold, deck, board, call, knockout
[A]: knockout


[Q]: Category: guitar part 
Words: worried, fret, truss rod, notes, amp
[A]:
worried