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: guitar part 
Words: inlays, concerned, string, notes, fret
concerned

Category: ocean 
Words: current, flow, course, early, moon

early