Whitebeam \White"beam`\, n. (Bot.) The common beam tree of England ({Pyrus Aria}); -- so called from the white, woolly under surface of the leaves. [1913 Webster]
Beam tree \Beam" tree`\ [AS. be['a]m a tree. See {Beam}.] (Bot.) A tree ({Pyrus aria}) related to the apple. [1913 Webster]