deciduous

adjective

de·​cid·​u·​ous di-ˈsi-jə-wəs 

-jü-əs

1

biology : falling off or shed seasonally or at a certain stage of development in the life cycle

deciduous leaves

deciduous scales

2

biology

a

: having deciduous parts

maples, birches, and other deciduous trees

deciduous dentition

b

: having the dominant plants deciduous

a deciduous forest

3

: ephemeral

There is much that is deciduous in books …

—J. R. Lowell

deciduousness noun

Synonyms of deciduous

• temporary
• flash
• brief
• transient
• passing
• ephemeral
• transitory

Examples of deciduous in a Sentence

the bare branches of a deciduous tree in winter

he chose not to fret about the deciduous discomforts of his existence

Recent Examples on the Web

Generally speaking, mature avocado trees should be soaked every two weeks, mature citrus trees every three weeks, and mature deciduous trees once a month. —Joshua Siskin, Oc Register, 16 Apr. 2026

The gray fox is a similar but different species that prefers deciduous forests. —Arricca Elin Sansone, Southern Living, 16 Apr. 2026

Sandhills, mixed-grass, and tallgrass prairies, plus western coniferous, eastern deciduous, and boreal forests live near each other there and nowhere else in the country. —Matt Crossman, Midwest Living, 14 Apr. 2026

Thanks to its dense, flexible branching structure, rapid growth habit, and deep, strong taproots that anchor it firmly, this deciduous tree excels in windy conditions. —Sj McShane, Martha Stewart, 8 Apr. 2026

Word History

Etymology

Latin deciduus, from decidere to fall off, from de- + cadere to fall — more at chance

First Known Use

1657, in the meaning defined at sense 1

Phrases Containing deciduous

• deciduous tooth

Kids Definition

deciduous

adjective

de·​cid·​u·​ous di-ˈsij-ə-wəs 

1

: falling off (as at the end of a growing period or stage of development)

antlers are deciduous

deciduous leaves

2

: having deciduous parts or members with deciduous parts

deciduous trees

a deciduous forest

Medical Definition

deciduous

adjective

de·​cid·​u·​ous di-ˈsij-ə-wəs 

1

: falling off or shed at a certain stage in the life cycle

2

: having deciduous parts

a deciduous dentition