The Collaborative International Dictionary of English v.0.48:

Upholstery \Up*hol"ster*y\, n.
   The articles or goods supplied by upholsterers; the business
   or work of an upholsterer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

upholstery
    n 1: covering (padding and springs and webbing and fabric) on a
         piece of furniture
    2: the craft of upholstering

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "upholstery":
   blanketing, blocking, blotting out, cementwork, cloaking, clouding,
   coating, coverage, covering, curtaining, eclipse, eclipsing,
   envelopment, enwrapment, enwrapping, hiding, incrustation,
   laying on, mantling, masking, obduction, obscuring, occultation,
   overlaying, overspreading, pargeting, plasterwork, screening,
   sheathing, shielding, shrouding, stuccowork, superimposition,
   superposition, upholstering, veiling, wrapping