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macadam, tarmac, tarmacadam
1. A paving for roads or other surfaces, formed by grading and compacting layers of crushed stone or gravel; then the top layer(s) are usually bound by asphaltic material, acting to stabilize the stone, provide a smoother surface, and seal against water penetration.
2. The crushed stone used in a macadamized surface.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.