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.
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Question: Category: bird 
Words: davit, egret, heron, crane, swift

Answer: davit


Question: Category: physical property 
Words: protein, pasty, fat, thin, angular momentum

Answer: protein


Question: Category: direction 
Words: south, loveful, down, left, falling

Answer:
loveful