IPA: /ˌʌndərɪkˈsplɔɪtɪd/
KK: /ʌndərɪkˈsplɔɪtɪd/
Not used or developed to its full potential or advantage.
The region is underexploited, with many resources that could benefit the local economy.
Underexploited → It is formed from "under-" (meaning below or insufficiently) and "exploited" (from Latin "exploitatus", meaning to utilize or make use of). The word describes a situation where something is not utilized to its full potential or is insufficiently exploited.
Think of something being used 'insufficiently' ('under-') — that's why underexploited means not fully utilized.