undeveloped; backward; unexplored
Used for countries, regions, resources, or fields that are not yet developed or exploited. Often carries a slightly formal or news-report tone. 'Backward' can sound dated or pejorative; prefer 'undeveloped' or 'less developed' in neutral contexts.
Undeveloped areas still have abundant nature.
That country has many undeveloped resources.
This jungle is still undeveloped.
This country has many undeveloped resources.
The government has left this region undeveloped.