Here are some possibilities:
From "populus" meaning "people":
* Popular: Widely liked or accepted by the general public.
* Population: The total number of people living in a particular area.
* Popularize: To make something widely known or accepted.
From "populare" meaning "to people":
* Populate: To live in or occupy a place.
* Depopulate: To reduce the number of people living in a place.
From "populace" meaning "the common people":
* Populist: A person who appeals to the common people.
* Populism: A political approach that strives to appeal to ordinary people who feel that their concerns are not being addressed by the elite.
Let me know if you have a specific meaning in mind, and I can give you a more precise answer.