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: emotional status 
Words: descending, disgusted, down, miserable, emotional

Answer: descending


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

Answer: concrete pourer


Question: Category: window material 
Words: glass, spyhole, knife, fiberglass, metal

Answer:
knife