'guardrail' definitions:

Definition of 'guardrail'

From: WordNet
noun
A railing placed alongside a stairway or road for safety [syn: safety rail, guardrail]

Definition of 'guardrail'

From: GCIDE
  • guardrail \guard"rail`\ n. a railing placed alongside a stairway or road for safety.
  • Syn: safety rail. [WordNet 1.5]