Volumetric is an adjective that describes something relating to volume or having to do with measuring volume. Some synonyms that could be used instead of volumetric are voluminous, capacious, spacious, expansive, roomy, bulky, or big. Voluminous means large in volume or size, just like the word capacious, which means able to hold a lot of things. Spacious is similar to volumetric in that it means having a lot of room or space inside, while expansive means taking up a lot of space. Roomy and bulky are more specific to physical objects and mean ample space for movement or large and cumbersome respectively, while big just means having a large volume.