An uproar is a great noise of shouting and protest — a room in uproar, a decision that caused an uproar. It is loud and it is angry, and both parts are needed: a cheering crowd is not an uproar.
The word is used most in journalism, where an uproar is what follows something a lot of people object to at once. It is usually uncountable after in — the meeting was in uproar — and countable with a: there was an uproar about the fee. The adjective is uproarious, which has drifted somewhere else entirely and now mostly means very funny, as in uproarious laughter.
1nounuproarA loud noise of shouting and angry protest.
“The announcement caused an uproar.”
synonyms: outcry, commotion, furore
2nounstateA state of noisy disorder.
“The hall was in uproar before the chairman could speak.”
Too few real examples of this word to estimate which sense is commonest.
uproar is a loud disturbance.
Uproar looks like up plus roar and is not. It came from Dutch oproer, meaning a revolt or an uprising, which English heard as a word about noise and respelled to match. The roar was invented by the ear, and the sense followed the spelling.
German
Aufruhr
Dutch
oproer
English, today
uproar
Dutch oproer or German Aufruhr, as up + roar.
Etymology from Wiktionary, CC BY-SA