up·stream [upstream] BrE [ˌʌpˈstriːm] NAmE [ˌʌpˈstriːm] (also less frequent up·river) adverb ~ (of/from sth) along a river, in the opposite direction to the way in which the water flows •The nearest town is about ten miles upstream. •upstream of/from the bridge Opp: ↑downstream See also: ↑upriver