Source : Webster's Revised Unabridged Dictionary (1913)

Menhir \Men"hir\, n. [F. Armor. men stone + hir high.]
   A large stone set upright in olden times as a memorial or
   monument. Many, of unknown date, are found in Brittany and
   throughout Northern Europe.

Source : WordNet®

menhir
     n : a tall upright megalith; found primarily in England and
         northern France [syn: {standing stone}]