東とう海かい道どう本ほん線せんMeaningsNoun1. Tokaido Main LineKanji used東east海sea道roadway本book線lineComposed of東とう海かい道どうTōkaidō (Edo-period Edo-Kyoto highway); Tōkaidō (under the ritsuryō system; one of the seven districts of ancient Japan)Noun本ほん線せんmain line; trunk lineNoun