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: outdoor sport activity 
Words: hiking, climbing, mice, fish, row
mice

Category: physical property 
Words: obese, heavy, area, chunky, fat
heavy

Category: military rank 
Words: lieutenant, average, commander, general, captain

average