Here are some other variations:
* "Lolo" (most common and general term)
* "Tatay" (used for father, but can also be used for grandfather, especially if the father is deceased)
* "Ama" (more formal term for father, but can also be used for grandfather in formal situations)
* "Apo" (literally means "grandchild," but can be used to address a grandfather respectfully)
The specific word used will depend on the context and the relationship between the speaker and the grandfather.