2 Chainz -- Sued for Five Million ... Over 'THOT' Video

2 Chainz might be forced to fork over $5,000,000 ... all because he called some woman a "THOT."

The woman in question, Christine Chisholm, says she was invited backstage at a 2 Chainz show on March 20, 2014 by one of Chainz's friends, rapper Cap 1.

In the video, Chainz repeatedly refers to Chisholm as a "THOT" ... an acronym for "that ho over there."

According to the lawsuit, Chisholm claims two weeks after the video was posted -- and was seen by 10 million people -- she was fired from her job at a barber shop because the manager thought the video would bring negative publicity to the shop.

Chisholm claims being called a ho subjected her to harassment and abuse in public and has severely damaged her reputation ... and she wants $5,000,000 in damages.