the oath of allegiance taken by roman soldiers; hence, a sacred ceremony used to impress an obligation; a solemn oath-taking; an oath.-the pledge or token of an oath or solemn covenant; a sacred thing; a mystery.-one of the solemn religious ordinances enjoined by christ, the head of the christian church, to be observed by his followers; hence, specifically, the eucharist; the lord's supper.-to bind by an oath.