A skateboarding trick where you ollie, pull your front truck over the rail, and slide on your deck, perpendicular to the rail. Arguably the easiest grind trick.
a snowboarding or skate trick. when you pop onto a box or rail, turning your body 90 degrees backwards, landing with your deck in a boardslide (perpendicular to the feature) facing uphill or backwards as you slide down the rail.
"yo, did you see that kid's frontside boardslide on that DFD rail, sickk..."