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.

Category: animal 
Words: bus, leap, spider, run, fly
bus

Category: weather 
Words: brisk, unprejudiced, fair, endure, clime
unprejudiced

Category: card games 
Words: whisky, war, pinochle, blackjack, gin

whisky