roadbed

[ rohd-bed ]
/ ˈroʊdˌbɛd /
|

noun

Railroads.
  1. the bed or foundation structure for the track of a railroad.
  2. the layer of ballast immediately beneath the ties of a railroad track.
the material of which a road is composed.

Origin of roadbed

1830–40. Americanism; road + bed
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for roadbed

British Dictionary definitions for roadbed

roadbed

/ (ˈrəʊdˌbɛd) /

noun

the material used to make a road
a layer of ballast that supports the sleepers of a railway track
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012