What's the difference between dolmen and dolven?

Dolmen

Definition:

• (n.) A cromlech. See Cromlech.

Example Sentences:

• (1) According to Dolmen Securities in Dublin, there are signs that much of the demand was "internationally based."
• (2) The region is also famous for its prehistoric artwork and dolmen burial sites.

Dolven

Definition:

• (p. p.) of Delve.

Example Sentences: