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]: fly, grasshopper, walk, waggle, train
[A]: train


[Q]: crew, board, deck, rudder, hull
[A]: board


[Q]: digger, swallow, swift, crane, goose
[A]:
digger