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

“Even if you can find a use case or some utility for it, you cannot actually guardrail away some of these inherent harms,” she said.

From Salon ● Aug. 17, 2026

Members of both parties have proposed guardrail legislation this year.

From Los Angeles Times ● Aug. 12, 2026

For companies moving fast on AI, that may be the guardrail that matters most right now.

From The Wall Street Journal ● Aug. 7, 2026

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

From Barron's ● Jul. 1, 2026

The operator reaches over us and pulls the guardrail down, locking us in.

From "Simon vs. the Homo Sapiens Agenda" by Becky Albertalli

The natural level of trust means that you might not apply the same rules as you would in a normal commercial relationhsip, so better guardrails are needed, she says.

From BBC ● Aug. 27, 2026

The question facing schools may increasingly be where those guardrails should go.

From Salon ● Aug. 23, 2026

Chiu has a slightly different challenge, ensuring that giving priority to those safety and security guardrails doesn’t slow the company’s pace of innovation.

From The Wall Street Journal ● Aug. 20, 2026

Pennsylvania Gov. Josh Shapiro signed an executive order Tuesday placing strict guardrails on new data centers, joining several states that are moving to limit the facilities fueling artificial intelligence’s rise.

From The Wall Street Journal ● Aug. 18, 2026

If Annabelle ran on US Route 12 and not the desolate 200, she’d be facing blind curves, and navigating tight spaces next to guardrails and steep, forested cliffs.

From "A Heart in a Body in the World" by Deb Caletti