Brunt is a noun that refers to the worst part of a specified thing. 

Coming from middle English, our word of the day was once used to describe a violent blow. In more recent years, it is more likely to be used to figuratively refer to an emotional blow someone may receive through criticism or an insult. Example:

The brunt of Kevin’s rant was borne by Sheila. It was, after all, her bad decisions that he focused on during his angry harangue.