prime meridian primely • prime minister · · · Info · Definitions · Characters · · prime meridian · · Text Common · · Latin · · Scripts 14 · · Length 5 · · Syllables Definitions · · · (noun) meridian at zero degree longitude from which east and west are reckoned (usually the Greenwich longitude in England). Synonyms: prime meridian. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E p latin small letter p U+0070 r latin small letter r U+0072