klaxon /ˈklæksən/noun 1verb 1forms 3 noun1 •A loud electric alarm or horn, especially as used in automobiles in the early 20th century.When the claxon sounded they immediately stopped what they were doing and uncovered the Oerlikon. Paddy, who was ammunition feeder, stood by while Jock trained the 20mm gun around. — 2007 verb1 •To produce a loud, siren-like wail.He headed down the Embankment. It was noon precisely. Big Ben klaxoned the hour with blasts of servo whistle. — 1980 formsklaxoned · klaxoning · klaxons