Jambage (post)

Vertical post on each side of a portail (portal) or another baie (wall opening), supporting an arc (arch).
Jambages are sometimes decorated.
These very wide (or deep) jambages support the arches of one of the side portals of the Sacré-Cœur in Paray-le-Monial.
See also piédroit (synonym).

Sacré-Cœur - Paray-le-Monial