When a woman masturbates so furiously (often with the assistance of a vibe or dildo) that her clit feels like it's been pounded by a jackhammer.
Girl 1: "God, I gave myself three orgasms last night, but this morning I have a horrible case of jackhammer clit!"
Girl 2: "I know, right? It's that damn Hitachi, it just works too well!"
Girl 2: "I know, right? It's that damn Hitachi, it just works too well!"
by RedReplicant August 19, 2010