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: emotional status 
Words: descending, disgusted, down, miserable, emotional
descending

Category: employment activity 
Words: burn, promote, instruct, fire, ban

burn