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: guitar part 
Words: neck, strap lock, fret, angry, notes

SOLUTION: angry

PROBLEM: Category: type of rigidity 
Words: inflexible, tough, taut, firm, leverage

SOLUTION: leverage

PROBLEM: Category: bird 
Words: sandpiper, crane, derrick, flamingo, swallow

SOLUTION:
derrick