When someone does something spectacular,
amazing, and/or unbelievable, like
Steve Nash would do on the basketball
court.
Dude, the way you did that back flip was nashty!
After killing 10
people in a row in
Halo, my friend said, "Shit man, that was nashty!"
When I saw this
kid playing basketball, and he did a 360 spin and threw the ball up, and it miraculously went in, I thought to myself, "man, that was nashty!"