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The black stuff on the road is alternately called asphalt, pavement or tarmac.
Tarmac was originally a registered trademark from 1903 and the black, smelly, gooey consistency of the stuff as it’s steam-rollered in place gives an obvious clue to the tar part of the word.
Before roads were essentially glued in place with tar they began as tracks through the mud. Horses and wagons regularly almost disappeared into these impediments to transportation and thus a star was born when the Scottish surveyor John Loudon McAdam invented a new kind of road.
First he dumped a bunch of rocks along the surface and after they got trampled into the grime by the passing traffic he added smaller and smaller stones and gravel to eventually form a roadbed similar to that beneath major highways today.
For this wonderful idea the new type of road was said to be McAdamized, after John McAdam.
John was long dead before anyone thought to glue the gravel together with tar, but they kept honoring him anyway and so do we, since its from his name that we get the mac in tarmac.
Five days a week Charles Hodgson produces Podictionary – the podcast for word lovers, Thursday episodes here at OUPblog. He’s also the author of several books including his latest History of Wine Words - An Intoxicating Dictionary of Etymology from the Vineyard, Glass, and Bottle.