Lil Mo Says Fat Joe's 'Dusty Bitches' Diss is Vile and Triggering

Lil Mo is calling out Fat Joe for referring to her as a dusty bitch crackhead during "Verzuz" ... saying he's way outta line, and totally insensitive to all people battling addiction.

Here's the deal ... Fat Joe came under fire after ripping Lil Mo and another female rap legend, Vita, during his Tuesday night musical showdown with Ja Rule. He said Ja must have found them in a "crack house."

Lil Mo tells TMZ ... Fat Joe's comments are "vile" and "disrespectful" and he should know better than to use those degrading terms, especially in light of recent celeb deaths, like Michael K. Williams, from drug problems.

In fact, Lil Mo says Joe's disses were actually triggering to her, because -- even though she's clean now -- she's dealt with her own opioid addiction issues in the past.

Fat Joe ended up apologizing publicly -- he also says he told Lil Mo and Vita sorry to their faces -- and Remy Ma rushed to his defense on social media, but Lil Mo says he shouldn't get off the hook so easy.