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: fish, iguana, canyoning, hamster, horse
canyoning

Category: weather 
Words: tangle, ghostly, fair, raining, sunny
ghostly

Category: employment activity 
Words: fire, hire, ground, pay, retire

ground