ˌOrdnance ˈSurvey ˌmap noun [countable] British English[
Date: 1800-1900;
Origin: Because the maps were originally made for the department responsible for ordnance: ordnance 'military materials' (14-20 centuries), from Old French ordenance]
a map which shows all the roads, paths, hills etc of an area in detail
[TahlilGaran] Dictionary of Contemporary English ▲