Nicki Minaj BLASTS Ex-Wig Guru -- I'm Washing You Out of My Fake Hair

Nicki Minaj is laughing off a $30 MILLION lawsuit from her former wig designer ... claiming the guy is nothing without her -- and hinting he fried his career like a bad perm by pissing her off.

Minaj just filed her response to Terrence Davidson's suit ... and she brushes it off as sour grapes "because he lost his most famous client."

Nicki also dismisses Davidson's claim she prevented him from becoming a reality TV star ... claiming he can't possibly land a show without her. Or as she put it in the docs, "his self-described talents are insufficient to garner the same types of business opportunities he may have received when serving as Mrs. Maraj's hairstylist."

Translation ... have fun working at SuperCuts.

Nicki wants a judge to toss Davidson's lawsuit.