This is the origin of the word as far as I know. Two opposing ramps originally used for BMXers, but now used by snow boarders, roller bladers, skateboards and others. See also quarter pipe.
I heard they're building a new half-pipe down at the park this summer. Let's try it out but I'm not down with wearing all of the armor they are going to require.
by Tentochi February 11, 2005
by King of Half'rs January 15, 2005
When wearing pants...the fact that the zipper area curls into a curved surface resembling the formation of a halfpipe. also looks like you have an erection
by hey!steve May 27, 2005
A term for a skateboard ramp that looks like a U, named a half-pipe because it is essentially half of a full pipe.
by tomtom not johnjohn April 23, 2011
by Jonathan and Carl January 09, 2004
by fhqwhgads May 05, 2003
by halfpipeasaurus March 17, 2011