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

Mythos’s unexpected sandbox breakout—which bypassed its own security guardrails—has surprised many security researchers and sparked vital discussions. —Kemba Walden, Fortune, 23 Apr. 2026

The constitutional guardrails are gone. —John Whitehead, Oc Register, 23 Apr. 2026

Officials say distillation efforts can weaken guardrails designed to ensure outputs remain accurate and controlled. —Aamir Khollam, Interesting Engineering, 23 Apr. 2026

Under the plan, FISA, which allows warrantless wiretapping of noncitizens, would be extended for three years, with new oversight guardrails and penalties for abusing the spy tool. —Hailey Bullis, The Washington Examiner, 23 Apr. 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)