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: weather 
Words: equitable, fair, windy, cold, raining
Example Output: equitable

Example Input: Category: physical property 
Words: thin, brittleness, heavy, angular momentum, fat
Example Output: heavy

Example Input: Category: geographical property 
Words: smooth, horizontal, even, smooshed, flat
Example Output:
even