Top definition
A phrase used when someone is being dumb or obviously didn't think out what they were about to say before they said it.
Teacher: "In this story, can anybody tell me what symbolizes death?"
Girl: "Whats death?"
Guy: "Really? You're straight derpin' right now"
by TheHerpaDerp March 22, 2011
Get the mug
Get a Derpin' mug for your mama Helena.