'Headstone' definitions:

Definition of 'headstone'

(from WordNet)
noun
The central building block at the top of an arch or vault [syn: keystone, key, headstone]
noun
A stone that is used to mark a grave [syn: gravestone, headstone, tombstone]

Definition of 'Headstone'

From: GCIDE
  • Headstone \Head"stone`\ (-st[=o]n`), n.
  • 1. The principal stone in a foundation; the chief or corner stone. --Ps. cxviii. 22. [1913 Webster]
  • 2. The stone at the head of a grave. [1913 Webster]

Synonyms of 'headstone'

From: Moby Thesaurus