ETYM Latin sacramentum an oath, a sacred thing, a mystery, a sacrament, from sacrare to declare as sacred, sacer sacred: cf. French sacrement. Related to Sacred.
A formal religious act conferring a specific grace on those who receive it.
In Christian usage, observances forming the visible sign of inward grace. In the Roman Catholic Church there are seven sacraments: baptism, Holy Communion (Eucharist or mass), confirmation, rite of reconciliation (confession and penance), holy orders, matrimony, and the anointing of the sick.