underdeveloped

adjective

un·​der·​de·​vel·​oped ˌən-dər-di-ˈve-ləpt 

1

: not normally or adequately developed

underdeveloped muscles

underdeveloped film

2

: having a relatively low economic level of industrial production and standard of living (as from lack of capital)

underdeveloped nations

underdevelopment

ˌən-dər-di-ˈve-ləp-mənt 

noun

Examples of underdeveloped in a Sentence

The baby was born with underdeveloped lungs.

Recent Examples on the Web

In August, Journey was taken to Blythedale Children's Hospital, where she was treated for a congenital heart condition known as PDA, as well as ongoing breathing challenges caused by underdeveloped lungs. — Nick Caloway, CBS News, 2 Nov. 2026

And as formidable as Seydoux can be, the character isn’t so much heartbreakingly conflicted as she is oddly muddled and underdeveloped. — Los Angeles Times, 30 Oct. 2026

This is where the AI conversation is still underdeveloped among business leaders. — Channing Ferrer, Forbes.com, 30 Oct. 2026

But until the full-scale war in Ukraine began, in 2022, these ideas remained underdeveloped. — Dmitry Adamsky, Foreign Affairs, 21 Oct. 2026

Word History

First Known Use

1892, in the meaning defined at sense 1

Rhymes for underdeveloped

• developed
• enveloped
• redeveloped
• undeveloped

Kids Definition

underdeveloped

adjective

un·​der·​de·​vel·​oped ˌən-dər-di-ˈvel-əpt 

1

: not developed normally or enough

underdeveloped muscles

2

: having a low level of industrial production and standard of living

the underdeveloped nations

Medical Definition

underdeveloped

adjective

un·​der·​de·​vel·​oped ˌən-dər-di-ˈvel-əpt 

: not normally or adequately developed

underdeveloped muscles

underdeveloped lungs