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: moral characteristic 
Words: just, make the grade, well, unjust, fair

SOLUTION: make the grade

PROBLEM: Category: bird 
Words: crane, concrete pourer, goose, hoist, duck

SOLUTION: concrete pourer

PROBLEM: Category: boxing terminology 
Words: rudder, ring, tko, deck, apron

SOLUTION:
rudder