sacrament

Concise Oxford English Dictionary © 2008 Oxford University Press:
sacrament /ˈsakrəm(ə)nt/

▶noun

• 1 (in the Christian Church) a religious ceremony or ritual regarded as imparting divine grace, such as baptism, the Eucharist, and (in the Catholic and many Orthodox Churches) penance and the anointing of the sick.

• 2 (also the Blessed Sacrament or the Holy Sacrament) (in Catholic use) the consecrated elements of the Eucharist, especially the bread or Host.

• 3 a thing of mysterious or sacred significance; a religious symbol.

– origin ME: from OFr. sacrement, from L. sacramentum ‘solemn oath’, used in Christian L. as a translation of Gk mustērion ‘mystery’.