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: outdoor sport activity 
Words: swim, wrestle, fish, canyoning, horse
Example Output: horse

Example Input: Category: window material 
Words: panel, translucent fabric, spatula, metal, glass
Example Output: spatula

Example Input: Category: aesthetic characteristic 
Words: beautiful, prime, bright, fine, dull
Example Output:
prime