Gusset /(?)/

Gus·set

Gusset

n.
  1. A small piece of cloth inserted in a garment, for the purpose of strengthening some part or giving it a tapering enlargement.
    Seam and gusset and band.
  2. Anything resembling a gusset in a garment (Armor)
  3. An abatement or mark of dishonor in a coat of arms, resembling a gusset. (Her.)