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: emotional status 
Words: fret, truss rod, emotional upsets, sad, worried
truss rod

Category: activity 
Words: blow, waste away, sweet roll, whittle, fritter
sweet roll

Category: construction 
Words: hoist, concrete pourer, dump truck, crane, neck

neck