walla

Sometimes seen in film terminology, the word 'walla' is a term for background conversation in a film scene.

Also referred to as 'rhubarb' because, traditionally, this is the word that film extras mutter to create the effect of background conversation.

My first nodeshell rescue!!

"Walla" means "Really?" in Arabic. Notice its definition already includes a question mark, so you don't have to pronounce a question tone when you say "Walla".
The same word was borrowed by Hebrew slang, and it's also the name of an established news/index portal (www.walla.co.il).