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

• 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

This may suggest that current safety guardrails and training methods may not address these gaps in AI outputs, and that a potentially dangerous sycophancy problem persists across different model generations. —ArsTechnica, 11 July 2025

The project is set to include a bridge deck overlay, concrete surface repairs, approach paving and guardrail replacement, according to the release. —Liliana Fannin, jsonline.com, 9 July 2025

The inspections evaluated Camp Mystic on dozens of different safety and compliance rules on topics from water supply to bunk bed guardrails. —Casey Tolan, CNN Money, 8 July 2025

But a new bill out of California would put some guardrails around exactly how much power artificial intelligence is allowed to have over human beings in the office. —Brit Morse, Fortune, 3 July 2025

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)