Lab"a*rum (), 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 (CHR)<-- appearing as English XP --> of the name of Christ in its Greek form. Later, the name was given to various modifications of this standard.
<-- Illustration of monogram, an X (Greek CHI) superimposed on a lengthened P (Greek RHO) -->
© Webster 1913.