A [skateboarding] trick that is often called a [boardslide], but if you know the history of the move, it is easy to differentiate between the two.

Back in the 60's and 70's, before people skated [rails] and [ledges], they skated [halfpipes] and [bowls]. If you wanted to do a boardslide/lipslide, you would ride up the side of the [vert], and get one of your [trucks] over the [lip], slide sideways a little ways, and then probably drop back in. This is where the difference in [nomenclature] comes in.

If you lifted your front [truck] up as you approached the lip, and slid, you did a [boardslide]. If you spun a [180] quickly, and had your rear truck above the lip, that was a lipslide. This is still the standard used today. That is, if the rear truck is lifted over the object, it's a lipslide. Front truck, it's a boardslide.

Of course, some old-schoolers don't call it a lipslide unless there is a lip, as in that of a halfpipe or bowl. I tend to disagree, because having more and more complicated names for tricks is entertaining.

lipslide (thing)