[lab-er-uh
m] 
[-er-uh] . | 1. | an ecclesiastical standard or banner, as for carrying in procession. |
| 2. | the military standard of Constantine the Great and later Christian emperors of Rome, bearing Christian symbols. |
| lab·a·rum (lāb'ər-əm) n. pl. lab·a·ra (-ər-ə)
[Late Latin, probably from alteration of Greek labrāton, laurel-leaf standard, from Latin laureātum, neuter of laureātus, adorned with laurel; see laureate.] |
labarum
sacred military standard of the Christian Roman emperors, first used by Constantine I in the early part of the 4th century AD. The labarum-a Christian version of the vexillum, the military standard used earlier in the Roman Empire-incorporated the Chi-Rho, the monogram of Christ, in a golden wreath atop the staff. The flag was made of purple silk (purple dye being at this time a rarity derived from a shellfish of the genus Murex) richly embroidered with gold. Although usually suspended from a horizontal bar, it appears to have been displayed occasionally by fastening one of its sides to its staff. In the Middle Ages the pastoral staff of a bishop often had attached to it a small purple scarf known as the vexillum, supposedly derived from the labarum.
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