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: type of rigidity 
Words: unbending, unyielding, inflexible, firm, streamline

SOLUTION: streamline

PROBLEM: Category: bird 
Words: neck, tackle, derrick, crane, steam roller

SOLUTION: steam roller

PROBLEM: Category: aesthetic characteristic 
Words: milky, even, fair, clime, pale

SOLUTION:
clime