'Roadbed' definitions:

Definition of 'roadbed'

From: WordNet
noun
A bed supporting a road

Definition of 'Roadbed'

From: GCIDE
  • Roadbed \Road"bed`\, n. In railroads, the bed or foundation on which the superstructure (ties, rails, etc.) rests; in common roads, the whole material laid in place and ready for travel. [1913 Webster]

Synonyms of 'roadbed'

From: Moby Thesaurus