[gus.set] n [ME, piece of armor covering the joints in a suit of armor, fr. MF gousset] (ca. 1570) 1: a usu. diamond-shaped or triangular insert in a seam (as of a sleeve, pocketbook, or shoe upper) to provide expansion or reinforcement
2: a plate or bracket for strengthening an angle in framework (as in a building or bridge) -- gusset vt