Meaning: "People"
* Population: The total number of people living in a particular area.
* Popular: Liked or admired by many people.
* Populate: To live in or occupy a place.
* Populace: The ordinary people of a country or area.
* Popularize: To make something known or liked by many people.
Meaning: "Sound"
* Pop: A sudden, sharp sound.
* Popping: The act of making a popping sound.
* Poppycock: Nonsense; foolish talk.
Meaning: "Food/Drink"
* Popcorn: A type of corn that explodes when heated.
* Popsicle: A frozen treat made with flavored water or juice.
* Pop: A type of fizzy carbonated beverage.
Other
* Poppy: A type of flowering plant with bright, colorful petals.
* Populous: Having a large population.
* Popularism: A political movement that appeals to the common people.
This is not an exhaustive list, and there are many other words with the root "pop." Remember that the meaning can vary depending on the context.