1. a road surface made of layers of small broken stones compacted together, often bound with tar or asphalt
Usage: Named after Scottish engineer John Loudon McAdam; Often used in the phrase 'tarmacadam' or 'tarmac'

Examples

• The new macadam road was smooth and durable.
• Workers laid macadam on the highway to improve its surface.
• The macadam parking lot was repaired after the winter damage.
• Macadam roads became popular in the 19th century.
• The driveway was paved with macadam instead of concrete.
• Heavy traffic can cause macadam surfaces to crack over time.