An Etymological Dictionary of the German Language/Annotated/Backbord
Backbord, neuter, ‘larboard,’ from Low German (compare the preceding word); compare Dutch bakboord (Anglo-Saxon bœcbord), whence also the equivalent French bâbord; literally ‘the left side of the ship to the back of the helmsman, who is steering with his right hand, the left hinder-part of the ship.’ Dutch and English back is an Old Teutonic word, which was, however, very early obsolete in High German (see the following word); Old High German bah, Old Saxon bak, Anglo-Saxon bœc, English back, Old Icelandic bak, neuter, ‘back,’ Gothic *bak, neuter. From Low German is also derived High German Bord. See the latter.