main deck main course • main diagonal · · · Info · Definitions · Synonyms · Characters · · main deck · · Text Common · · Latin · · Scripts 9 · · Length 2 · · Syllables Definitions · · · (noun) the uppermost sheltered deck that runs the entire length of a large vessel. Synonyms: main deck, second deck. · · Noun Definition 1 Synonyms · · · second deck · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 k latin small letter k U+006B m latin small letter m U+006D n latin small letter n U+006E