1 definition by Gre3narr0w
A way to proclaim that you have a partial boner or "Semi" to your male friends so women won't know what you're talking about.
"Man, Katie was all over me last night, she gave me an 18 wheeler"
"I had a total 18 wheeler when Danica was sitting on my lap at the water park"
"I had a total 18 wheeler when Danica was sitting on my lap at the water park"
by Gre3narr0w June 25, 2014