An Etymological Dictionary of the German Language/Annotated/Boje

by Friedrich Kluge

Boje, feminine, ‘buoy,’ from the Low German boje, Dutch boei, English buoy, which are borrowed from Romance; compare French bouée, ‘buoy,’ Old French buie, ‘chain, fetter', whence Middle High German boie, ‘fetter'. The ultimate source of the word is Latin boja, ‘fetter’; the buoy was originally a floating piece of wood with a rope fastened to it.