Source : Webster's Revised Unabridged Dictionary (1913)

Sarsen \Sar"sen\, n. [Etymol. uncertain; perhaps for saracen
   stone, i.e., a heathen or pagan stone or monument.]
   One of the large sandstone blocks scattered over the English
   chalk downs; -- called also {sarsen stone}, and {Druid
   stone}. [Eng.]