The Collaborative International Dictionary
Topstone
Topstone \Top"stone`\, n. A stone that is placed on the top, or which forms the top.
Wiktionary
topstone
n. A stone that is placed on the top, or which forms the top.
Usage examples of "topstone".
Angel hugged Kristen fully, then let go and reached for her gloves and shears off the flat topstones of the rock wall.