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.

Example Input: Category: boxing terminology 
Words: ring, lifeline, deck, punch, corner
Example Output: lifeline

Example Input: Category: type of rigidity 
Words: solid, leverage, hard, unbending, firm
Example Output: leverage

Example Input: Category: outdoor sport activity 
Words: hunt, row, wrestle, fish, hamster
Example Output:
hamster