Meaning:

“毒” is short for “恶毒的,” which means “vicious,” and “舌” literally means “tongue.” Originating from Japanese animation, comics and games, this term is used to describe people who like to judge people, find fault with them and as a result undermine their confidence. Not necessarily using rude language, those who are acid-tongued are often hurtful and overdoing it when they criticize people.

Example:

A: 听说小林和他女朋友分手了。

Tīngshuō xiǎolín hé tā nǚpéngyǒu fēnshǒu le 。

I’ve heard that Xiao Lin broke up with his girlfriend.

B: 是啊，小林说，受不了她的毒舌，总被她打击自信。

Shì ā ，xiǎolín shuō ，shòubùliǎo tā de dúshé ，zǒng bèi tā dǎjī zìxìn 。

Yeah. Xiao Lin said he could not put up with her any more. She’s always acid-tongued, and her criticism has undermined his self confidence.