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Webster 1913 Edition

adv.

In the proper position of an altar, that is, at the east of a church with its ends towards the north and south.

Shipley.

altarwise ‎(not comparable)

Placed in the manner of an altar, against the eastern wall of the chancel with the longer side parallel to that wall.
- 2009, George Gresley Perry, A History of the English Church
  But usually, when not used, the tables stood altarwise against the east wall.