n. An oath of obedience and fidelity taken by Roman soldiers on enlistment; hence, any oath, solemn engagement, or obligation, or ceremony that binds or imposes obligation.n. In theology, an outward and visible sign of inward and spiritual grace; more particularly, a solemn religious ceremony enjoined by Christ, or by the church, for the spiritual benefit of the church or of individual Christians, by which their special relation to him is created or freshly recognized, or their obligations to him are renewed and ratified.n. The eucharist, or Lord's Supper: used with the definite article, and without any qualifying word.To bind by an oath.