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: temperature 
Words: cold, hot, cool, popular, relaxing
popular

Category: animal 
Words: fish, iguana, canyoning, hamster, horse
canyoning

Category: season 
Words: winter, hiems, leaves, stoop, fall

stoop