Greenwich Mean Time
From Longman Dictionary of Contemporary EnglishRelated topics: ChronologyGreenwich Mean TimeGreen‧wich Mean Time /ˌɡrenɪtʃ ˈmiːn taɪm, ˌɡrɪ-, -nɪdʒ-/ noun [uncountable] (abbreviation GMT) TMCthe time as measured at Greenwich in LondonExamples from the CorpusGreenwich Mean Time• Mr Schofield usually went round at twelve o'clock Greenwich Mean Time rewinding and resetting.• You could have set Greenwich Mean Time by the great vaudeville comedians.