ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: Middle English sour dogh, from sour (I) + dogh dough — more at dough
1. : a leaven consisting of dough in which both alcoholic and lactic fermentation is active
2.
[so called from the use of sourdough in making bread while camping]
: a veteran inhabitant (as an old-time prospector) of Alaska or northwestern Canada — contrasted with cheechako