‖n.; pl. Labara [ L. ] The standard adopted by the Emperor Constantine after his conversion to Christianity. It is described as a pike bearing a silk banner hanging from a crosspiece, and surmounted by a golden crown. It bore a monogram of the first two letters (ΧΡ) (which appear like the English letters X and P), of the name of Christ in its Greek form. Later, the name was given to various modifications of this standard. [ 1913 Webster ]

‖n.; pl. L. Labra E. Labrums [ L. ] 1. A lip or edge, as of a basin. [ 1913 Webster ]

2. (Zool.) (a) An organ in insects and crustaceans covering the upper part of the mouth, and serving as an upper lip. See Illust. of Hymenoptera. (b) The external margin of the aperture of a shell. See Univalve. [ 1913 Webster ]