NOUN (2)

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;

The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

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