/diˈsijo͞oəs/
Adjective
1. Means “falling off at maturity” or “tending to fall off”, and is typically used in reference to trees or shrubs that lose their leaves seasonally, 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. (wikipedia.org)
2. Refers to a plant (usually a tree or shrub) that sheds its leaves at the end of the growing season. (biology-online.org)
3. Denoting the milk teeth of a mammal, which are shed after a time. (Google Dictionary)
4. Describing a part that falls off, or is shed, at a particular time or stage of development. (biology-online.org)
Word origin: From Latin dēciduus (“falling down or off”), from dēcidō (“fall down”)