IPA: /ˌʌndərˈpɒpjʊleɪtɪd/
KK: /ʌndərˈpɑpjuˌleɪtɪd/
Having fewer people living in an area than is typical or needed.
The town is underpopulated, making it difficult to sustain local businesses.
Underpopulated → It is formed from "under-" (meaning below or insufficient) and "populated" (from Latin "populatus", meaning to populate or fill with people). The word describes an area that has a population below what is considered normal or sufficient.
Think of 'under-' meaning below and 'populated' meaning filled with people — so underpopulated means there are not enough people in a place.