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.
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Question: Category: animal 
Words: bird, flutter, jump, waggle, fly

Answer: flutter


Question: Category: direction 
Words: down, opposite of up, sliding, forward, emotional state

Answer: emotional state


Question: Category: boxing terminology 
Words: canvas, tko, deck, joker, fight

Answer:
joker