From Longman Dictionary of Contemporary Englishsurface mailˈsurface ˌmail noun [uncountable] TCMthe system of sending letters or packages by land or sea, rather than by airFrom Longman Business Dictionarysurface mailˈsurface ˌmail the system of sending letters etc by ship, train, or road, rather than by airIf you do not write ‘airmail’ on the envelope, the letter will be sent by surface mail. → compare airmail → mail
