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: weather 
Words: sunny, alright, deal, fair, tangle
alright

Category: secretary duty 
Words: support, type, file, software, answer
software

Category: measurement unit 
Words: heel, pound, foot, kilometer, meter

heel