OPTIO, an officer in the Roman army, who was an assistant or lieutenant to the centurion. The optio was so called because in later times he was the choice or option of the centurion; at first, however, he derived his appointment from the tribune or commander of the legion. Sometimes the optiones were also called succenturiones and tergiductores; the latter name having been given them because their post was in the rear of the company. Several authors mention sub-optiones or sub-lieutenants. It is proper, however, to add, that optiones were not peculiar to the camp, but were also employed in a variety of other offices.
OR, the French word for gold, by which this metal is expressed in heraldry. In engraving it is denoted by small points all over the field or bearing.