What is the meaning of the term sacramentum?

Sacramentum is a Latin term, arguably derived from the prefix sacra-, meaning "holy", and -ment, meaning "mind". The latin Word Sacrament has historically been translated to "oath".

A sacrament, in the Eastern Orthodox and Western Catholic traditions is one of seven rites, or ritual ceremonies, which serve as both a cause of sanctifying grace and as a sign of God's blessing/presence.

The Sacraments are baptism, confirmation, and marriage (rites of commitment); confession, penance, and anointing (rites of healing); and communion/Eucharist (the most sublime rite, signifying both commitment and healing).

In the Orthodox and Catholic traditions, strictly speaking, Deacons may perform baptisms and marriages; priests and monsignori may perform all sacraments except confirmation; bishops perform all sacraments. Baptism may be performed by anyone in extreme cases.