n. downhill skateboard
, usually built very heavy duty measuring 40-43" with wheel cutouts for large wheels. often mounted drop-through, with the truck baseplate mounted on top of the board.
v. downhill skateboarding
, where riders use aerodynamic tucks and crouches to reach speeds as high as 65mph, drifting their boards at turns and footbraking, airbraking, or sliding to stop.
n. I just got a brand new speedboard! I can't wait to bomb some hills!
v. Hey, do you want to speedboard today? I found a nice hill over by the school.