Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
underpopulated is an adjective meaning "having a lower population density than normal or desirable". It carries one recorded sense.
having a lower population density than normal or desirable
“the richly endowed but underpopulated Ivory Coast”
Definitions, synonyms and semantic relations for underpopulated come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.