tarmac

"Tarmac" is a clipping of "tarmacadam," a blend of "tar" and "macadam" (crushed stones). It was originally a trademark owned by its inventor, Edgar Hooley.

What began as the proprietary name for a specific paving product was shortened over time to the everyday word we use for paved surfaces, especially airport runways.

It shares its second half with "macadam," the crushed-stone road surface it was built from.