TASK DEFINITION: Given a set of five words, generate the word from the set that does not belong (i.e. is the least relevant) with the other words. Words are separated by commas.
PROBLEM: parrot, goose, crane, swallow, excavator

SOLUTION: excavator

PROBLEM: prime, penalty, fine, mad, arrest

SOLUTION: mad

PROBLEM: angry, board, fret, emotional state, bored

SOLUTION:
board