Engaged order

Engaged Order: decorative order projecting from but forming an integral part of the wall against which it stands
Exedra: a semicircular or rectangular recess open on one side to a lobby or court ...

engaged order: columns attached to or sunk into a wall or pier.
entablature: the upper horizontal part of an order consisting of (from top to bottom) cornice, frieze and architrave.

See also: Metope, Apex, Trave, Temple, Member