A guardrail is a railing that is placed along the edge of something such as a staircase, path, or boat, so that people can hold onto it or so that they do not fall over the edge.
guardrail in British English
(ˈɡɑːdˌreɪl)
noun
1.
a railing at the side of a staircase, road, etc, as a safety barrier
2. Also called (Brit): checkrail railways
a short metal rail fitted to the inside of the main rail to provide additional support in keeping a train's wheels on the track
guardrail in American English
(ˈgɑrdˌreɪl)
noun
1.
a railing that serves as a protective barrier, as on a staircase or alongside a highway
2. US
an extra rail alongside the main rail of a railroad at a crossing, etc., as to keep the cars on the track
Examples of 'guardrail' in a sentence
guardrail
Traffic was reportedly separated by only a temporary guardrail.