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: accomodation 
Words: mansion, mountain, flat, house, duplex

Answer: mountain


Question: Category: employment activity 
Words: promote, ice, retire, ban, fire

Answer: ice


Question: Category: activity 
Words: fritter, divide, squander, doughnut, waste away

Answer:
doughnut