gmt gmelinite • gnabble · · · Info · Definitions · Characters · · gmt · · Text Latin · · Script 3 · · Length 1 · · Syllables Definitions · · · (noun) the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere. Synonyms: Greenwich Mean Time, Greenwich Time, GMT, universal time, UT, UT1. · · Noun Definition 1 Characters · · g latin small letter g U+0067 m latin small letter m U+006D t latin small letter t U+0074