Source : Webster's Revised Unabridged Dictionary (1913)

Dolmen \Dol"men\, n. [Armor. taol, tol, table + mean, maen, men,
   stone: cf. F. dolmen.]
   A cromlech. See {Cromlech}. [Written also {tolmen}.]

Source : WordNet®

dolmen
     n : a prehistoric megalith typically having two upright stones
         and a capstone [syn: {cromlech}]