Source : Webster's Revised Unabridged Dictionary (1913)

Forefather \Fore"fa`ther\ (?; 277), n.
   One who precedes another in the line of genealogy in any
   degree, but usually in a remote degree; an ancestor.

         Respecting your forefathers, you would have been taught
         to respect yourselves.                   --Burke.

   {Forefathers' Day}, the anniversary of the day (December 21)
      on which the Pilgrim Fathers landed at Plymouth,
      Massachusetts (1620). On account of a mistake in reckoning
      the change from Old Style to New Style, it has generally
      been celebrated on the 22d.

Source : WordNet®

forefather
     n 1: the founder of a family; "keep the faith of our forefathers"
          [syn: {father}, {sire}]
     2: person from an earlier time who contributed to the tradition
        shared by some group; "our forefathers brought forth a
        great nation"