WordNet (r) 3.0 (2006):

foundation garment
    n 1: a woman's undergarment worn to give shape to the contours
         of the body [syn: foundation garment, foundation]

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "foundation garment":
   advocate, alpenstock, arm, athletic supporter, back, backbone,
   backing, bandeau, bearer, bra, brace, bracer, bracket, brassiere,
   buttress, cane, carrier, cervix, corselet, corset, crook, crutch,
   fulcrum, girdle, guy, guywire, jock, jockstrap, mainstay,
   maintainer, mast, neck, prop, reinforce, reinforcement, reinforcer,
   rest, resting place, rigging, shoulder, shroud, spine, sprit,
   staff, standing rigging, stave, stay, stays, stick, stiffener,
   strengthener, support, supporter, sustainer, upholder,
   walking stick