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: activity 
Words: dally, goodbye, fritter, whittle, dumpling
dumpling

Category: moral characteristic 
Words: unprejudiced, unjust, milky, ok, fair
milky

Category: accomodation 
Words: plain, mansion, condominium, squashed, flat

plain