klaxon

American  

[klak-suhn] / ˈklæk sən /

Or claxon

noun

1. a loud electric horn, formerly used on automobiles, trucks, etc., and now often used as a warning signal.

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klaxon British  

/ ˈklæksən /

noun

1. a type of loud horn formerly used on motor vehicles

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Etymology

Origin of klaxon

An Americanism dating back to 1905–10; formerly trademark

Explanation

A klaxon is a warning horn or signal that's used on a vehicle. While the sound of a klaxon is a little old-fashioned these days, its loud blast will still get your attention. Most people who attempt to describe the sound of a klaxon come up with something like "AH-OOH-GA," and in fact it's not uncommon to call a klaxon an "ahooga horn." The word klaxon is actually trademarked, describing a specific mechanical horn first made by the Klaxon Company in 1908. The sound of a klaxon was once a common noise on busy streets, at train crossings, and even on boats.

Example Sentences

See Examples For:

klaxon

Nobody rings a bell, as they say, but sometimes we have a conversation or an experience that sets off a klaxon in our heads.

From The Wall Street Journal ● Jun. 8, 2026

Speaking about the protests, Kyle said on Sunday with Laura Kuenssberg moments like these were "klaxon calls" for those in power to redouble their efforts to address the big concerns people have, including on immigration.

From BBC ● Sep. 14, 2025

Johnson, who is testifying under oath, admitted Wednesday that he made mistakes in grasping the extent of the pandemic and that his advisers failed to sound a “loud enough klaxon of alarm” about the virus.

From Seattle Times ● Dec. 7, 2023

Thus the first pandemic klaxon warnings in the White House were sounded by a different set of experts.

From Washington Post ● Dec. 29, 2020

Each time, when the system saw that I’d drifted off, it sounded a warning klaxon in my ears, jolting me back awake.

From "Ready Player One: A Novel" by Ernest Cline