— triforial , adj.
/truy fawr"ee euhm, -fohr"-/ , n. , pl. triforia /-fawr"ee euh, -fohr"-/ . Archit.
(in a church) the wall at the side of the nave, choir, or transept, corresponding to the space between the vaulting or ceiling and the roof of an aisle, often having a blind arcade or an opening in a gallery.
[ 1695-1705; triforium kind of gallery, lit., something with three openings, equiv. to L tri- TRI- + for ( is ) opening, DOOR + -ium -IUM ]