A tree of the genus Fagus.
- A deciduous tree of the genus Fagus having smooth gray bark, alternate simple leaves, and three-angled nuts enclosed in prickly burs. The best-known species are F. grandifolia of eastern North America and the European species F. sylvatica and its numerous cultivated forms.
- The wood of any of these trees, used for flooring, containers, plywood, and tool handles.
- Any of several other woody plants, as in the genera Carpinus and Nothofagus.