means a sacred religious rite, especially in Christianity, believed to convey divine grace through a physical sign like bread, water, or oil.

from From Latin sacramentum, which originally meant a sum of money deposited in a sacred place, then a soldier's solemn oath of loyalty — built on sacer, 'holy, set apart.' Early Christian writers borrowed the word to translate the Greek mysterion ('mystery'), so the soldier's binding vow became the believer's binding sign; the same root 'sacer' threads through sacred, sacrifice, and consecrate.