Definitions

1. noun

a stone slab or coping laid above the top of a wall, particularly a coping stone on the top of a wall or parapet, or the topmost stone of an arch or other structure.

“The copingstone of the old castle’s wall had been worn away by the passage of time.”

2. verb

to cover or cap with a copingstone

“The stonemasons were tasked with coping the top of the wall with a new stone slab.”