Definitions of birch:

• noun:   bundle of birch twigs used to hit people as punishment
• noun:   any betulaceous tree or shrub of the genus Betula having a thin peeling bark
• noun:   hard close-grained wood of any of various birch trees; used especially in furniture and interior finishes and plywood
• verb:   whip with a birch twig
• adjective:   consisting of or made of wood of the birch tree
• name:  A surname (rare: 1 in 25000 families; popularity rank in the U.S.: #3012)