de·mili·ta·rize demilitarizes demilitarizing demilitarized in BRIT, also use demilitarise To demilitarize an area means to ensure that all military forces are removed from it. He said the UN had made remarkable progress in demilitarizing the region + demilitarization de·mili·ta·ri·za·tion Demilitarization of the country was out of the question. to remove the weapons, soldiers etc from a country or area so that there can be no fighting there