from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Falling off or shed at a specific season or stage of growth: deciduous antlers; deciduous leaves; deciduous teeth.
- adj. Shedding or losing foliage at the end of the growing season: deciduous trees.
- adj. Not lasting; ephemeral.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Describing a part that falls off, or is shed, at a particular time or stage of development.
- adj. Of or pertaining to trees which lose their leaves in winter or the dry season.
- adj. transitory, ephemeral, not lasting
from the GNU version of the Collaborative International Dictionary of English
- adj. Falling off, or subject to fall or be shed, at a certain season, or a certain stage or interval of growth, as leaves (except of evergreens) in autumn, or as parts of animals, such as hair, teeth, antlers, etc.; also, shedding leaves or parts at certain seasons, stages, or intervals
from The Century Dictionary and Cyclopedia
- Falling or liable to fall, especially after a definite period of time; not perennial or permanent.
- Specifically— In botany: Falling off at maturity or at the end of the season, as petals, leaves, fruit, etc.: in distinction from fugacious or caducous organs, which fall soon after their appearance, and from persistent or permanent, or, as applied to leaves, from evergreen. Losing the foliage every year: as, deciduous trees.
- In zoology: Falling off at a certain stage of an animal's existence, as the hair, horns, and teeth of certain animals. Losing certain parts regularly and periodically, or at certain stages or ages: as, a deciduous insect.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. (of plants and shrubs) shedding foliage at the end of the growing season
- adj. (of teeth, antlers, etc.) being shed at the end of a period of growth
From Latin dēciduus, from dēcidere, to fall off : dē-, de- + cadere, to fall; see kad- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin dēciduus ("falling down or off"), from dēcidō ("fall down") (Wiktionary)