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.
--------
Question: Category: poker 
Words: board, joker, deck, fold, apron

Answer: apron


Question: Category: type of sandwich 
Words: roll, hoagie, bacon, club, community

Answer: community


Question: Category: measurement unit 
Words: ounce, foot, kilometer, milimeter, heel

Answer:
heel