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: bird 
Words: winch, swift, crane, hoist, ostrich
Example Output: winch

Example Input: Category: emotional status 
Words: down, emotional state, loveful, ashamed, flat
Example Output: flat

Example Input: Category: physical property 
Words: fat, chunky, area, bulky, calcium
Example Output:
calcium