Convexness is a mathematical term used to describe the shape of a curved object that is bulging outward. However, there are several synonyms for convexness that can be used interchangeably depending on the context. One synonym is "protrusion," which implies an object that is bulging outwards or sticking out from its surroundings. "Bulging," "swelling," and "jutting" are also synonyms for convexness, suggesting that an object is protruding from its normal shape or position. In addition, "curvature" and "roundness" can be used to describe the convex shape of an object. These synonyms can be useful in describing a variety of shapes, from the curvature of a ball to the bulge of a pregnant woman's belly.