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.

Category: boxing terminology 
Words: deck, gunwale, level, tko, jab
gunwale

Category: geographical property 
Words: horizontal, hotel, flat, lined, smooth
hotel

Category: aesthetic characteristic 
Words: well, neat, fine, exquisite, level

well