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: weather 
Words: raining, cold, sunny, alright, fair
alright

Category: measurement unit 
Words: ounce, foot, kilometer, milimeter, heel
heel

Category: direction 
Words: downward, down, kind, falling, south

kind