TASK DEFINITION: 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.
PROBLEM: Category: elements 
Words: ice, air, fire, hire, combustion

SOLUTION: hire

PROBLEM: Category: employment activity 
Words: recruit, replace, sack, heat, fire

SOLUTION: heat

PROBLEM: Category: moral characteristic 
Words: brash, courage, honest, vittles, frank

SOLUTION:
vittles