General:
* Protruding
* Swelling
* Expanding
* Distended
* Puffed
* Convex
* Prominent
* Outwardly curved
* Rounded
More specific:
* If it's about the eyes: Protruding, bulging, protruding, popping, protuberant
* If it's about a muscle: Swelling, bulging, straining, taut, tight, tense
* If it's about a container: Distended, full, overflowing, overflowing, swollen
* If it's about a shape: Convex, rounded, curved
It would be helpful if you could provide more context. For example, what is bulging? Is it a muscle, a part of the body, a container, or something else? Knowing more about the situation will help me provide you with the most accurate synonym.