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.

---

klaxon British  

/ ˈklæksən /

noun

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

---

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

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

FA Cup: Sound the :”magic” klaxon - we have our first upset of the weekend as Burnley go out to Huddersfield Town.

From The Guardian ● Jan. 8, 2022

People outside the cordon do not need to evacuate if they hear the klaxon sounded, the council said.

From BBC ● Aug. 3, 2021

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