Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.

Q: prime, penalty, fine, mad, arrest

A: mad
****
Q: foot, knee, eye, leg, ounce

A: ounce
****
Q: medium, well, level, fair, equitable

A:
equitable
****