Here are some examples of words using the prefix "grav-":
* Gravity: The force of attraction between any two objects with mass.
* Gravitate: To move towards something, especially as if drawn by an unseen force.
* Grave: A place where a dead person is buried.
* Gravid: Pregnant.
* Gravitation: The act or process of being drawn towards something.
The prefix "grav-" can also imply importance or seriousness, as in the word "grave" (meaning serious or dangerous).
Keep in mind that the meaning of the prefix can vary slightly depending on the specific word it's part of.