Deciduous means "temporary" or "tending to fall off" (deriving from the Latin word decidere, to fall off).
Deciduousplants, principally trees and shrubs, are those that lose their foliage for part of the year. In most cases, the foliage loss coincides with the incidence of winter in temperate or polar climates, but some plants lose their leaves during dry seasons in arid climates. Non-deciduous plants are known as evergreens.
Deciduous teeth, also called milk teeth, are those that fall out during the course of normal development. Other body parts that are shed, such as antlers, are also described as deciduous.
Deciduous forests can be found in the eastern half of North America, and the middle of Europe.
The types of trees you can find in these three regions are broad leafed deciduoustrees and some of the evergreen species.
Most deciduous forests are found in Eastern North America somewhere around 35-48° N, and Europe and Asia around 45-60° N. There are some deciduous regions in the southern hemisphere but their plants and animals are different from those of the northern deciduous forests.