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.

[Q]: Category: season 
Words: winter, roll, spring, hiems, fall
[A]: roll


[Q]: Category: activity 
Words: fritter, waste, pie, waste away, lollygag
[A]: pie


[Q]: Category: construction 
Words: excavator, digger, crane, steam roller, egret
[A]:
egret