The Collaborative International Dictionary of English v.0.48:

Matelass'e \Mate`las`s['e]"\ (m[.a]`l[.a]`s[asl]"), a. [F., p.p.
   of matelasser to cushion, to cover as with a mattress, fr.
   matelas mattress. See Mattress.]
   Ornamented by means of an imitation or suggestion of
   quilting, the surface being marked by depressed lines which
   form squares or lozenges in relief; as, matelass['e] silks.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Matelass'e \Mate`las`s['e]"\, n.
   A quilted ornamented dress fabric of silk or silk and wool.
   [Webster 1913 Suppl.]