the outer angle made by the flexure or bend of the arm. That eminence whereon the arm rests, called by us elbow, is by the Latins called cubitus, and by the Greeks ἄγκυστος, and by others ἄγκυστος.

Elbow is also used by architects, masons, and others, for an obtuse angle of a wall, building, or road, which diverts it from its right line.