consisting of or forming a large mass; bulky and heavy

massive columns.

large and heavy-looking

a massive forehead.

large in scale, amount, or degree

a massive breakdown in communications; massive reductions in spending.

solid or substantial; great or imposing

massive erudition.

Mineralogy . having no outward crystal form, although sometimes crystalline in internal structure.

noun

heftiness , ponderosity , ponderousness , weight , weightiness