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: physical activity 
Words: trip, jump, fall, equinox, exercise
equinox

Category: weather 
Words: windy, stormy, fair, tone, tangle
tone

Category: food 
Words: meat, frank, sausage, entree, fortitude

fortitude