Synonyms of 'undeveloped'
An embryonic process, idea, organization, or organism is one at a very early stage in its development.
Romania's embryonic democracy
Something or someone that is immature is not yet completely grown or fully developed.
The birds were in immature plumage.
Thesaurus for undeveloped from the Collins English Thesaurus
An undeveloped country or region does not have modern industries and usually has a low standard of living .