noun

1. any of a genus (Betula) of trees and shrubs of the birch family, having smooth bark easily peeled off in thin sheets, and hard, closegrained wood: found in northern climates
2. the wood of any of these trees
3. a birch rod or bunch of twigs used for whipping

Etymology: ME birche < OE beorc < IE base *bhereĝ-, to gleam, white > bright

transitive verb

adjective

1. designating a family (Betulaceae, order Fagales) of dicotyledonous shrubs and trees, including the hazels, alders, and hornbeams
2. of birch
   also birchen birch′en