underminiac 

Noun. A word blend of undermine and maniac. Depicts someone who cannot help them self from making undermining comments. As with kleptomania the underminiac is largely unconscious of this behavior even though it might seem like they take sadistic gratification from it. Their victims are often left realizing how badly they were trashed for days and weeks afterward as many of the undermining comments are not initially obvious.

Lunch with that underminiac will leave your ego in a coma for weeks afterwards.

underminiac by Swampybaby January 6, 2017

undermining 

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

undermining by La SAPE August 18, 2019

Undermineantinonnallyiltyer 

When u add whatever the fuck to a word

Undermineantinonnallyiltyer Is a completely ducking useless word

Undermineantinonnallyiltyer by QSXDRFVGYHNJI June 4, 2023