Performing a motorcycle jump or stunt and landing hard enough to compress the bike's suspension to the point of hitting the frame or 'case' on the ground.
To get absolutely drilled, snapped, smashed, whipped, woopanged, basically to get severely injured (can be whilst doing a dangerous activity or can be unintentional).
Parri just got cased!
Ry-daddy cased his leg after pummelling into some random.
That random just cased himself on a pole!