type of large forest tree noted for its smooth, silvery bark and its mast, which serves as food for animals, Old English bece "beech," earlier boece, from Proto-Germanic *bokjon (source also of Old Norse bok, Dutch beuk, Flemish boek, Old High German buohha, German Buche, Middle Dutch boeke "beech"), from PIE root *bhago- "beech tree" (cognate with Greek phegos "oak," Latin fagus "beech;" see fagus). Formerly with adjectival form beechen. Also see book (n.).