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
Examples of underdeveloped in a Sentence
The baby was born with underdeveloped lungs.
Recent Examples on the Web
Infant botulism is a serious illness that develops when an infant ingests spores of the botulinum bacteria, which then colonize the baby’s underdeveloped gut and begin producing a toxin.
—
Brenda Goodman, CNN Money, 29 Dec. 2025
Juvenile snow geese are being hit particularly hard because of their underdeveloped immune systems and the toll migration can take, according to the Kansas Department of Wildlife and Parks (KDWP).
—Kendrick Calfee, Kansas City Star, 17 Dec. 2025
Other Indigenous characters, like the Orphan Lilla Belle (Natalia Del Riego) and Constance’s consigliere Jack Cree (Michael Greyeyes, squandered), are similarly underdeveloped.
—Judy Berman, Time, 4 Dec. 2025
Like many children born to mothers infected with Zika while pregnant, Tamara had microcephaly — an underdeveloped brain.
—Ari Daniel, NPR, 29 Nov. 2025
See All Example Sentences for underdeveloped
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Brenda Goodman, CNN Money, 29 Dec. 2025
Juvenile snow geese are being hit particularly hard because of their underdeveloped immune systems and the toll migration can take, according to the Kansas Department of Wildlife and Parks (KDWP).
—Kendrick Calfee, Kansas City Star, 17 Dec. 2025
Other Indigenous characters, like the Orphan Lilla Belle (Natalia Del Riego) and Constance’s consigliere Jack Cree (Michael Greyeyes, squandered), are similarly underdeveloped.
—Judy Berman, Time, 4 Dec. 2025
Like many children born to mothers infected with Zika while pregnant, Tamara had microcephaly — an underdeveloped brain.
—Ari Daniel, NPR, 29 Nov. 2025
See All Example Sentences for underdeveloped
Cite this Entry
“Underdeveloped.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/underdeveloped. Accessed 30 Dec. 2025.
Copy CitationKids 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
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