Longtime Oklahoma assistant Cale Gundy -- who's been helping coach the Sooners football team for over two decades -- has resigned ... after he says he uttered a "shameful and hurtful" word during a team meeting last week.
Gundy explained the situation in a lengthy statement on his social media page Sunday night -- saying he inadvertently used the word while reading off a player's iPad in a film session.
"I instructed my players to take notes," said the 50-year-old, who had just been tapped this offseason to coach the Sooners receivers this year.