IPA: /ˈpɒp.jʊ.ləs/
KK: /ˈpɑp.jə.ləs/
Having a lot of people living in a particular area; crowded with inhabitants.
Tokyo is one of the most populous cities in the world.
Populous → It is formed from "populus" (meaning people or population) and the suffix "-ous" (meaning full of). The word "populous" means full of people or densely populated.
Think of 'populus' which means people, and remember that 'populous' describes a place that is full of people.