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: type of sandwich 
Words: grilled cheese, french toast, outing, burger, club
outing

Category: police punishment 
Words: hearing, firstrate, alert, custody, fine
alert

Category: window material 
Words: bowl, lead, vinyl, glass, plastic

bowl