Deciduous means "falling off at maturity" or "tending to fall off", and it is typically used in order to refer to
trees or
shrubs that lose their
leaves seasonally (most commonly during
autumn) and to the shedding of other plant structures such as
petals after flowering or
fruit when ripe. In a more general sense,
deciduous means "the dropping of a part that is no longer needed" or "falling away after its purpose is finished". In plants it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous
antlers in
deer or
deciduous teeth, also known as baby teeth, in some mammals (including humans).