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: physical activity 
Words: run, jump, autumn, fall, swim

Answer: autumn


Question: Category: boxing terminology 
Words: ring, lifeline, deck, punch, corner

Answer: lifeline


Question: Category: animal 
Words: fish, iguana, raft, shark, cow

Answer:
raft