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: bus, fly, swim, spider, flap

A: spider
****
Q: gunwale, deck, punch, sail, bow

A: punch
****
Q: flutter, cockroach, fly, swim, bats

A:
flutter
****