noun \mə-ˈka-dəm\

: a road surface made with a dark material that contains small broken stones

Full Definition of MACADAM

:  macadamized roadway or pavement especially with a bituminous binder

Origin of MACADAM

John L. McAdam †1836 British engineer
First Known Use: 1824


noun    (Concise Encyclopedia)

Form of pavement invented by John McAdam. McAdam's road cross-section consisted of a compacted subgrade of crushed granite or greenstone designed to support the load, covered by a surface of light stone to absorb wear and tear and shed water to the drainage ditches. In modern macadam construction, crushed stone or gravel is placed on the compacted base course and bound together with asphalt cement or hot tar. A third layer to fill the spaces is then added and rolled. Cement-sand slurry is sometimes used as the binder.


Next Word in the Dictionary: macadamia
Previous Word in the Dictionary: Macacus
All Words Near: macadam

Seen & Heard

What made you want to look up macadam? Please tell us where you read or heard it (including the quote, if possible).