deciduous

UK: /dɪˈsɪdjʊəs/ US: /dɪˈsɪdʒuəs/ ,(di sij′o̅o̅ əs)

WordReference Random House Learner's Dictionary of American English © 2025

de•cid•u•ous /dɪˈsɪdʒuəs/   adj. 

1. Botany losing the leaves every year:
   deciduous trees.
2. Botany shed at a particular season or stage of growth:
   deciduous teeth.

See -cide-².

WordReference Random House Unabridged Dictionary of American English © 2025

de•cid•u•ous  (di sij′o̅o̅ əs), adj. 

1. Botany shedding the leaves annually, as certain trees and shrubs.
2. Botany falling off or shed at a particular season, stage of growth, etc., as leaves, horns, or teeth.
3. not permanent;
   transitory.

• Latin dēciduus tending to fall, falling, equivalent. to dēcid(ere) to fall off, down (dē- de- + -cidere, combining form of cadere to fall) + -uus deverbal adjective, adjectival suffix; see -ous
• 1650–60

de•cid′u•ous•ly, adv. 
de•cid′u•ous•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

deciduous / dɪˈsɪdjʊəs/ adjective

1. (of trees and shrubs) shedding all leaves annually at the end of the growing season and then having a dormant period without leaves
   Compare evergreen1
2. (of antlers, wings, teeth, etc) being shed at the end of a period of growth
3. impermanent; transitory
   

Etymology: 17th Century: from Latin dēciduus falling off, from dēcidere to fall down, from cadere to fall

deˈciduousness noun