The Collaborative International Dictionary of English v.0.48:

macadam \macadam\ n.
   The broken stone used in macadamized roadways.
   [WordNet 1.5]

   2. A paved surface formed of compressed layers of broken
      rocks held together with tar.

   Syn: tartarmac, macadam.
        [WordNet 1.5] macadam

The Collaborative International Dictionary of English v.0.48:

macadam \macadam\ macadamized \macadamized\adj.
   1. paved with macadam[2].

   Syn: asphalt, tarmac, tarmacadam.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

macadam
    n 1: broken stone used in macadamized roadways
    2: a paved surface having compressed layers of broken rocks held
       together with tar [syn: tarmacadam, tarmac, macadam]