- a tree, Aesculus hippocastanum, native to the Old World, having digitate leaves and upright clusters of white flowers.
- the shiny, brown, nutlike seed of this tree or of other trees of the genus Aesculus.
- any of several trees of the genus Aesculus, esp the Eurasian A. hippocastanum, having palmate leaves, erect clusters of white, pink, or red flowers, and brown shiny inedible nuts enclosed in a spiky bur: family Hippocastanaceae
- the nut of this tree
