The Collaborative International Dictionary of English v.0.48:

Marble \Mar"ble\, v. t. [imp. & p. p. Marbled; p. pr. & vb. n.
   Marbling.] [Cf. F. marbrer. See Marble, n.]
   To stain or vein like marble; to variegate in color; as, to
   marble the edges of a book, or the surface of paper.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Marbled \Mar"bled\, a.
   1. Made of, or faced with, marble. [Obs.] "The marbled
      mansion." --Shak.
      [1913 Webster]

   2. Made to resemble marble; veined or spotted like marble.
      "Marbled paper." --Boyle.
      [1913 Webster]

   3. (Zool.) Varied with irregular markings, or witch a
      confused blending of irregular spots and streaks.
      [1913 Webster]

   4. Having small flecks of fat interspered with the muscle; --
      of cuts of meat, especially beef; as, a well-marbled
      steak. Such marbling improves the flavor of beef for most
      people.
      [PJC]

WordNet (r) 3.0 (2006):

marbled
    adj 1: patterned with veins or streaks or color resembling
           marble; "marbleized pink skin" [syn: marbled,
           marbleized, marbleised]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "marbled":
   banded, barred, brinded, brindle, brindled, calico, clouded,
   dapple, dappled, listed, marbleized, motley, mottled,
   pepper-and-salt, piebald, pied, pinto, skewbald, streaked, streaky,
   striatal, striate, striated, strigate, strigose, striolate,
   striped, stripy, tabby, veined, watered