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.

Category: shady activities 
Words: falsification, fib, invent, fudge, cupcake
cupcake

Category: social gathering 
Words: group, clan, team, club, doorstep
doorstep

Category: physical activity 
Words: swim, crouch, dog, bow, duck

dog