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: direction 
Words: up, descending, down, lower, melancholy
melancholy

Category: poker 
Words: fold, suits, deck, sail, hearts
sail

Category: moral characteristic 
Words: equitable, fair, impartial, just, well

well