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: chocolate food 
Words: brownie, loosen, chocolate cake, fudge, molasses
loosen

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

Category: emotional status 
Words: content, ecstatic, excited, substance, sad

substance