WordNet (r) 3.0 (2006):

decal
    n 1: either a design that is fixed to some surface or a paper
         bearing the design which is to be transferred to the
         surface [syn: decal, decalcomania]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "decal":
   adherent, adhesive, barnacle, bramble, brier, bulldog, burr,
   cameography, cement, decalcomania, glass printing, glue, gunk,
   leech, limpet, molasses, monotype, mucilage, paste, plaster,
   prickle, remora, serigraphy, stencil, sticker, syrup, thorn