Glenn Robinson: Stephen A. Smith's a Racist ... 'Skip's Crash Course Dummy'

Glenn "Big Dog" Robinson did NOT accept Stephen A. Smith's quasi-apology Tuesday morning -- in fact, he's even MORE pissed off now ... calls the guy a straight up racist.

Robinson just sent us a video response to Stephen A's comments on "First Take" this morning -- in which he apologized for bringing up old beef ... but said he stands by what he said.

Of course, Smith had called Robinson a racial hypocrite -- claiming Glenn talked about helping black coaches succeed in the NBA ... only to treat his former 76ers coach Randy Ayers (who's black) like "trash."

Watch the clip -- Glenn clearly takes offense ... and fires back at Smith in a big way.