diss
1. verb, slang To insult or disrespect someone. Did you hear what she said? You just got dissed, bro. These two rappers always seem to be dissing each other on Twitter.
2. noun, slang An insult or instance of disrespect; a put-down. A: "Nice ears, Dumbo." B: "Ooh, what a diss. Like I don't know my ears stick out, come on."