Having significant volume or spatial extent, independent of mass, density, or substance. Useful when words such as big, bulky, or massive incorrectly imply something about weight or mass.
Scientific: “Aerogel is extremely volumive relative to its mass.”
Everyday: “That family-size bag of chips was disappointingly volumive.”
Figurative: “His 47-slide presentation was impressively volumive but remarkably low in substance.”