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: baby animals 
Words: buck, bambi, lust, fawn, deer

Answer: lust


Question: Category: emotional status 
Words: concerned, board, nervous, emotional, fret

Answer: board


Question: Category: bird 
Words: concrete pourer, flamingo, egret, crane, duck

Answer:
concrete pourer