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: accomodation 
Words: apartment, cabin, squashed, smooth, flat
smooth

Category: moral characteristic 
Words: decent, impartial, light, fair, dishonest
light

Category: physical activity 
Words: sprint, get down, cow, duck, bow

cow