from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Pavement made of layers of compacted broken stone, now usually bound with tar or asphalt.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The surface of a road consisting of layers of crushed stone (usually tar-coated for modern traffic).
  • n. Any road or street

from the GNU version of the Collaborative International Dictionary of English

  • adj. paved with macadam{2}.
  • n. The broken stone used in macadamized roadways.
  • n. A paved surface formed of compressed layers of broken rocks held together with tar.

from The Century Dictionary and Cyclopedia

  • n. Macadamized pavement.
  • n. The material used for a macadam pavement.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. broken stone used in macadamized roadways
  • n. a paved surface having compressed layers of broken rocks held together with tar


from The American Heritage® Dictionary of the English Language, 4th Edition

After John Loudon McAdam (1756-1836), Scottish civil engineer.

from Wiktionary, Creative Commons Attribution/Share-Alike License

Named after John Loudon McAdam, who invented the process of macadamization. Used for describing road surfaces originally constructed using the McAdam method, but now sometimes used for any road or street.


  • To give you a feel for how long ago this was the main beneficiaries of the macadam were the new fangled bicycle-men.

    Matthew Yglesias » Mass Transit is As American as Apple Pie

  • The splendid kunkah is now gradually giving place to ordinary macadam, which is far less desirable, the heavy, pelting rain washing away the clay and leaving the surface rough.

    Around the World on a Bicycle - Volume II From Teheran To Yokohama

  • John McAdam designed the first modern highway of inexpensive paving material of soil and stone aggregate known as macadam during the Industrial Revolution.

    Recently Uploaded Slideshows

  • All was wild and solitary, and one might have declared it a scene untrodden by the foot of man, but for the telegraph posts and small piles of broken "macadam" at punctual intervals, and the ginger-beer bottles and paper bags of local confectioners that lent an air of civilisation to the road.

    Quest of the Golden Girl, a Romance

  • It was the first major road in the nation to employ the new system of "macadam" surface - a mixture of broken rock and tar.

    Daily Kos

  • "macadam" (a singular dish of rice stewed with salt fish -- _diri épi coubouyon lamori_), akras, etc.; but her bouts probably bring her the largest profit -- they are all bought up by the békés.

    Two Years in the French West Indies

  • A late-seventies model Ford Bronco sprawled like a brown dinosaur on the fresh macadam.

    Rogue Oracle

  • The maples, macadam, shadows, houses, cars were to his violated eyes as brilliant as a scene remembered: he became a child again in this town, where life was a distant adventure, a rumor, an always imminent joy.

    Updike, John

  • Others, of course, still require a smooth macadam surface.

    Washington D.C. weather in the year 2076, part II

  • It is no wonder we modern Americans don't sense moccasin trails under the macadam -- most traces of indigenous peoples are literally paved over.

    Alison Owings: The Buffalo In The Room: A Reflection For Native American Heritage Month


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  • "Eddie started pushing Susannah along the smooth macadam of the parking lot again, pointing to cars as they passed them." From Wizard and Glass by Stephen King.

    January 19, 2011

  • Cool, reesetee! I wasn't dreaming, there really was a guy named McAdam who paved roads. Whew!

    February 17, 2007

  • I think his family came to NY from Scotland. He lived mid-18th to mid-19th centuries. His family was apparently involved in the Revolutionary War.

    Here's some info I dug up quickly:

    Wikipedia's entry for macadam says: "While macadam roads have now been resurfaced in most developed countries, some are preserved along stretches of roads such as the United States' National Road. Due to uses of macadam as a road surface in former times, roads in some parts of the United States (e.g., parts of Pennsylvania) are often referred to as macadam, even though they might be made of asphalt or concrete."

    Seems to explain the Pennsylvania link to the word.

    February 15, 2007

  • Well, that would certainly make sense with the idea that it's a regionally known term in Pennsylvania. Was Mr. MacAdam (or was it Macadam?) a Scots immigrant to Pennsylvania, by any chance? I'm thinking late eighteenth, early nineteenth century at the latest, based on nothing but my vague memory...

    February 15, 2007

  • For what it's worth, I've never heard of this. My family speaks Michiganese, and I grew up in Florida. I now live in New Mexico. Haven't heard the word in any of those contexts.

    February 13, 2007

  • I've encountered that too--people who aren't from the same region not knowing this word. I'd always assumed it was more or less universal, but I've also heard it's a regional (PA) thing.

    There was a John McAdam--Scottish engineer, I believe. He invented a means to create roads that were smoother than those made of earth and called the process macadamisation. At first, it didn't include tar, but it was later added to keep dust down--and that is apparently where the word tarmac came from as well.


    February 13, 2007

  • I prefer to say this over "asphalt," or the even less desirable "blacktop," but apparently "macadam" is a regionalism and not many other people seem to know what I'm talking about.

    I remember learning years ago that it was a man named John MacAdam who invented the kind of paving we call asphalt. I don't know if that's true or one of those weird little memories I dredge up when I see this word.

    February 13, 2007