Populated means having people living in it. Somebody is there.
It is nearly always qualified, so densely populated, sparsely populated and thinly populated are the standard phrases, and the bare word is rare. Geography and planning use it constantly. There is a useful extended sense about filling anything with contents, so a database populated with records or a story populated by odd characters both work. The verb populate is used the same way, and the noun is population.
1adjectivepopulatedHaving inhabitants living there.
“The valley is very sparsely populated.”
Also accepted in games: inhabited
Latin
populus — people
Medieval Latin
populātus
English
populate
English, today
populated
Built from
populate Borrowed from Medieval Latin populātus, past participle of populor (“populate”), from Latin populus (“people”).
Etymology from Wiktionary, CC BY-SA