(adjective) A replacement word for the "f" word. It's origins date back to April 22, 2005 when a joke was made about an engrish phrase "Fack you man." It was said that the opposite of fack is nuck, but it's very tongue tying, and sometimes comes out as f*ck and nack, thus the word "nack".
Dude! That movie was nackin rad!
by potato-sensei July 07, 2006