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: luke, make the grade, fair, milky, deal

A: milky
****
Q: bow, fold, hull, deck, head

A: fold
****
Q: walk, fly, bike, jog, bird

A:
bird
****