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: bird, fish, fly, drive, eagle
drive

Category: secretary duty 
Words: file, organize, schedule appointments, answer calls, program
program

Category: boxing terminology 
Words: tko, stern, fight, caution, deck

stern