n.1 a table or flat-topped block, often of stone, for sacrifice or offering to a deity.
2 a Communion-table.
Phrases and idioms:
altar boy a boy who serves as a priest's assistant in a service. lead to the altar marry (a woman).
Etymology: OE altar -er, Gmc adoption of LL altar, altarium f. L altaria (pl.) burnt offerings, altar, prob. rel. to adolere burn in sacrifice