An ancient Greek or Roman galley having four rowers for each set of oars.
There is continuing uncertainty about the actual arrangement of oars on a quadrireme; the prevailing view among historians is that they were usually arranged in two banks, with two men on each oar. A design with four banks of oars is likely to have been unstable.
Late 16th century; earliest use found in William Harrison (1535–1593), historian and topographer. From classical Latin quadrirēmis type of galley, probably one with four rowers to every ‘room’, in post-classical Latin also as adjective from quadri- + rēmus oar, perhaps partly via Middle French quadrireme.