black birch n 1: common birch of the eastern United States having spicy brown bark yielding a volatile oil and hard dark wood used for furniture [syn: {sweet birch}, {cherry birch}, {black birch}, {Betula lenta}] 2: birch of swamps and river bottoms throughout the eastern United States having reddish-brown bark [syn: {black birch}, {river birch}, {red birch}, {Betula nigra}]