What is the X in X-mas?
U.S. history, one of a class of militia available for immediate service (i.e. "ready in a matter of minutes"), 1774. As the name of a type of ICBM, from 1961, so called because they could be launched with very little preparation.
: Youth gangs use minors as gun runners, calling them ''minutemen'' because if they're caught they're out (of jail) in a minute (1990s+ Street gang)