Definitions by Michelle- Belle

Chestnut 

Hard, when a boy sees something he finds sexually pleasing to the eye and he get all "happy" in the pants. e.g. hard on, stiff, erection etc

Guy 1: Dude, I'm so chestnut right now!

Dude: That chick is making me so chestnut!

Chestnut by Michelle- Belle March 22, 2008