guardrail

American  

[gahrd-reyl] / ˈgɑrdˌreɪl /

noun

guardrails plural

1. Also guardrailing. a protective railing, as along a road or stairway.

2. Railroads. a rail laid parallel to a track to prevent derailment or to keep derailed rolling stock from leaving the roadbed.

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guardrail British  

/ 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

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Other Word Forms

Noun Inflected Forms

• guardrails
  plural

Etymology

Origin of guardrail

First recorded in 1825–35; guard + rail ¹

Explanation

A guardrail is a strong fence at the side of the road that can help protect drivers from serious injury. On a highway, center guardrails make it easier to avoid colliding with a car going the opposite direction. Guardrails protect cars from hitting large roadside objects like trees and signs, or from hazards such as steep hills beside the highway. Additionally, guardrails are designed to keep cars upright, even when they strike the rail at fairly high speeds. In some places, low, protective fences around public spaces are also called guardrails — in this case, they're guarding against pedestrian injuries. "Stay back from the guardrail around the lion enclosure!"

Example Sentences

See Examples For:

guardrail guardrails

"This includes excellent work around advanced model access and guardrail testing and security."

From Barron's ● Jul. 1, 2026

“This is one of the first times that an AI company has rolled out a guardrail and there has been uniform disdain,” said Sayash Kapoor, an AI researcher at Princeton University.

From The Wall Street Journal ● Jun. 11, 2026

“Every time you take a guardrail away, there’s the possibility of confusion.”

From MarketWatch ● Apr. 24, 2026

The vehicle continues off the freeway, where it hits a guardrail and launches into the air, the video showed.

From Los Angeles Times ● Apr. 15, 2026

And there’s the Pigman, the smiling Pigman, leaning all the way over the guardrail, tossing peanuts to this mean baboon.

From "The Pigman" by Paul Zindel

But it's a topic that has sparked debate and calls for guardrails worldwide.

From Barron's ● Jul. 15, 2026

“We built Muse Image with strong controls and safety guardrails from day one,” Meta said in a statement.

From Los Angeles Times ● Jul. 9, 2026

The amendment has few guardrails on how judicial elections will operate, giving the Legislature unfettered authority to set the rules.

From Slate ● Jul. 8, 2026

“In absence of public policy that provides cultural norms or guardrails, your experience is entirely shaped by your manager,” she said.

From MarketWatch ● Jul. 7, 2026

It sailed up over the guardrails, through the cables, plunging off the middle span of the Ambassador Bridge.

From "Middlesex: A Novel" by Jeffrey Eugenides