An Etymological Dictionary of the German Language/Annotated/Zwinger

by Friedrich Kluge

Zwinger, masculine, ‘fortified castle, prison, narrow space, wild beast’s cage, arena,’ from Middle High German twingœre, masculine, ‘oppressor, space between the walls and ditch of a citadel, promurale, fortress.’ Compare Danish twinger, ‘prison, wild beast's cage’ (Dutch dwinger, ‘despot, tyrant’).