Main Entry: sour·dough

Pronunciation: \ˈsau̇(-ə)r-ˌdō, 1 is also -ˈdō\

Function: noun

Date: 14th century

1 : a leaven consisting of dough in which fermentation is active
2 [from the use of sourdough for making bread in prospectors' camps] : a veteran inhabitant and especially an old-time prospector of Alaska or northwestern Canada