on or to the left: a left-hand turn at the intersection.
of, for, or with the left hand.
3. Building Trades. a.
(of a door) having the hinges on the left when seen from the exterior of the building, room, closet, etc., to which
the doorway leads.
(of a casement sash) having the hinges on the left when seen from inside the window.
1150–1200; Middle English