Source : Webster's Revised Unabridged Dictionary (1913)

Structural shape \Struc"tur*al shape\ (Engin. & Arch.)
   The shape of a member especially adapted to structural
   purposes, esp. in giving the greatest strength with the least
   material. Hence, Colloq., any steel or iron member of such
   shape, as channel irons, I beams, T beams, etc., or,
   sometimes, a column, girder, etc., built up with such
   members.