Quick Quiz: Nouns Score: Change category, Flip order Reset Correct! Noun: sourdough Your choice? a family of dicotyledonous trees of order Myrtales that includes the sour gum trees a leaven of dough in which fermentation is active; used by pioneers for making bread a sullen moody resentful disposition a republic at the southernmost part of Africa; first European settlers were Dutch (known as Boers)