A minuteman was not an official soldier in a regular army. In the American past, especially in the 1770s around the War of Independence, he was a colonist in the militia — often a farmer or craftsman — who kept a gun and had promised to be ready to fight at a minute's notice. The Minutemen of Massachusetts are the ones schoolbooks mention most. The word is a piece of that history: you meet it in stories of alarms, village greens, and men leaving the plough. Write Minuteman with a capital M when you mean that famous group. Later the United States also gave the name to a kind of missile, but that is a different use; here the word means the ready civilian fighter. It does not mean a tiny man. The minute is the short time, not the adjective for small.