instruction:
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.
question:
Category: corporate 
Words: corporation, firm, synergy, tough, concerted
answer:
tough


question:
Category: boxing terminology 
Words: corner, fold, deck, knockout, level
answer:
fold


question:
Category: aesthetic characteristic 
Words: detailed, attractive, custody, pretty, fine
answer:

custody