instruction:
Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.
question:
Category: weather 
Words: brisk, ghostly, windy, fair, deal
answer:
ghostly


question:
Category: type of rigidity 
Words: inflexible, tough, taut, firm, leverage
answer:
leverage


question:
Category: bird 
Words: crane, derrick, goose, mallet, hummingbird
answer:

derrick