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: boats 
Words: bridge, deck, stern, dock, suits
Example Output: suits

Example Input: Category: emotional status 
Words: down, melancholy, below, loveful, kind
Example Output: below

Example Input: Category: corporate 
Words: private, firm, sustainability, rigged, synergy
Example Output:
rigged