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: window material 
Words: glass, coating, panel, spatula, lead
spatula

Category: activity 
Words: fritter, sweet roll, whittle, seperate, divide
sweet roll

Category: police punishment 
Words: penalty, firstrate, fine, money, detached

detached