The blunt metallic edge at the top of a halfpipe/quarterpipe. It serves two purposes: a. It is smooth and hence makes it easy to grind and b. When people come flying down from two metres above and smack their heads on the edge of the pipe (like Tony Hawk) they only break bones and get concussions rather than slicing their heads open.

Thank god for coping.

Cop"ing (?), n. [See Cope, n.] Arch.

The highest or covering course of masonry in a wall, often with sloping edges to carry off water; -- sometimes called capping.

Gwill.

 

© Webster 1913.