名詞 headstone:

1. the central building block at the top of an arch or vault
   同義詞：keystone, key
2. a stone that is used to mark a grave
   同義詞：gravestone, tombstone

head.stone

n.（名詞）
A memorial stone set at the head of a grave.
墓石：豎在墓前的紀念性石碑
Also head stone Architecture See keystone
也作 head stone 【建筑學】 參見 keystone