Definition of "altar"

altar

/ˈɔːl.tə/

noun
plural altars
1. A table or similar flat-topped structure used for religious rites.
  Quotations
  To hawke, or els to huntFrom the auter to the funt,Wyth cry unreverent,Before the sacrament,Wythin the holy church bowndis,That of our fayth the grownd is.
  c. 1503–1512, John Skelton, Ware the Hauke; republished in John Scattergood, editor, John Skelton: The Complete English Poems, 1983, page 62, lines 9–14
2. (informal) A raised area around an altar in a church; the sanctuary.
3. (figurative) Any (real or notional) place where something is worshipped or sacrificed to.
  Quotations
  […] now marking the end of ascetic rationalism, the monadology no longer implied a sacrifice of individuality on the altar of rationality.
  2000, Alain Renaut, M. B. De Bevoise, Era of the Individual: A Contribution to a History of Subjectivity