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

An additional challenge for nuclear deployment is grid capacity, since large nuclear reactors often produce too much power for underdeveloped grids. — Jenny Vaughan, semafor.com, 20 July 2026

What looks like a relationship falling apart is often reality catching up to something that was underdeveloped from the start. — Lyssanoel Frater, USA Today, 15 July 2026

About 70% of countries around the world have underdeveloped regulatory drug approval processes. — C. Michael White, The Conversation, 15 July 2026

The book certainly covers a lot of ground, and some threads inevitably seem underdeveloped, but the show moves along quite smoothly under Leigh Silverman’s direction. — Emily McClanathan, Chicago Tribune, 10 July 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