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: hiking, stingray, shark, fish, tiger

A: hiking
****
Q: falsification, fib, invent, fudge, cupcake

A: cupcake
****
Q: queen, deck, apron, board, check

A:
apron
****