Source : Webster's Revised Unabridged Dictionary (1913)

Minuteman \Min"ute*man\, n.; pl. {Minutemen}.
   A militiaman who was to be ready to march at a moment's
   notice; -- a term used in the American Revolution.

Source : WordNet®

Minuteman
     n 1: an American militiaman prior to and during the American
          Revolution
     2: a strategic weapon system using a guided missile of
        intercontinental range; missiles are equipped with nuclear
        warheads and dispersed in hardened silos