The number of sexual partners one has been with, especially regarding a man (hence the notch = pussy).
Brad: "Bro I'm twenty and I've already slept with three different bitches."
Chad: "Yo that's nothing I had a 20 notch count by the time I was 16!"
Chad: "Yo that's nothing I had a 20 notch count by the time I was 16!"
by Old for my age November 13, 2022