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: blow, waste away, fritter, dally, croquet

A: croquet
****
Q: concerned, fret, notes, frustrated, worried

A: notes
****
Q: rigged, unyielding, firm, resistant, united

A:
united
****