From Longman Dictionary of Contemporary EnglishRelated topics: Letters & punctuation, NumbersMM, m /em/ (plural M’s, m’s) noun1SLA[countable, uncountable] the 13th letter of the English alphabet2HMN[countable] the number 1,000 in the system of romannumerals3 →M6, M25 etcmm (also m.)1the writtenabbreviation of metre or metres2the written abbreviation of mile or miles3the written abbreviation of million4the written abbreviation of male5the written abbreviation of married6the written abbreviation of medium, used on clothes to mean an averagesizeFrom Longman Business Dictionarymmwritten abbreviation for METRE(S);MILE(S);MILLION