Picking out one's flaws in a derogatory manner. Also called reading. Used extensively in the gay community and especially in drag queen culture.
-Girl, you call yourself legendary! More like leg and dairy!
-Bitch, why you throwing shade?
-Was your barbeque canceled? Because your grill is fucked up!
-You throwing beaucoup shade!
-Jessica, those clothes look like a donkey fucked a piñata and threw up!
-Is the library closed yet? Because I'm tired of you throwing shade!