A person that will intentionally sabotage someone else through any means necessary.
He stole from me after I tried to help him, so I undermined him by making sure every business in the area knows that he is a shoplifter.

I am an underminer.
by Thingsda October 21, 2019
The act of under estimating something about someone or the act of making a person feel inferior to ur to your list of skills
You are undermining my knowledge bro
by La SAPE August 18, 2019
"...we are not going to undermine our community by creating or promoting alternative services..."
by JacobMS June 7, 2012
A reference that blacks use to describe a certain location
"Damn cuz, there is this sexy bitch that lives in the apartment undermine."
by Cwick21 February 26, 2008
A person who cockblocks a person with a vagina
I wanted to get with Nick so bad last night but Jennifer was being such a vagina underminer
by NocklasKongo March 6, 2021
someone who picks their nose and their butt at the same time
You know that one kid in our 2nd period? well he's an underminer.
by Freyasoupy January 21, 2021