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: physical property 
Words: brittleness, large, fat, area, calcium
calcium

Category: police punishment 
Words: prison, fine, calm, money, suspension
calm

Category: social gathering 
Words: grilled cheese, community, convention, dance hall, club

grilled cheese