guardrail

noun

guard·​rail ˈgärd-ˌrāl 

: a railing guarding usually against danger

especially : a barrier placed along the edge of a highway at dangerous points

Synonyms of guardrail

• railing
• rail

Examples of guardrail in a Sentence

the car ran off the road, but fortunately only hit the guardrail

Recent Examples on the Web

Like during OpenAI’s tests, normal safety guardrails were removed during Anthropic’s evaluations to assess their models’ full capabilities. — Hadas Gold, CNN Money, 31 July 2026

Despite the coalition’s effort to introduce AI guardrails, some labels involved have already inked partnerships with AI companies such as Suno, Udio and Nvidia. — Cerys Davies, Los Angeles Times, 30 July 2026

The work includes replacing the existing pavement and improving the shoulder lanes, median, guardrails, and signage. — Dan Raby, CBS News, 30 July 2026

OpenAI’s Rogue Agent Broke In In July, OpenAI was running a cybersecurity test against its models, including an unreleased research prototype, with the guardrails switched off for the exercise. — Jason Snyder, Forbes.com, 29 July 2026

Word History

First Known Use

1860, in the meaning defined above

Rhymes for guardrail

• airmail
• assail
• avail
• bewail
• blackmail
• cattail
• cocktail
• curtail
• derail
• detail
• dovetail
• email

Kids Definition

guardrail

noun

guard·​rail ˈgär-ˌdrāl 

: a protective railing placed along dangerous areas (as of a road)