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1. Imposing in size, bulk or solidity
   "massive oak doors"; "Moore's massive sculptures";
   - monolithic, monumental
    
2. Being the same substance throughout
   "massive silver"
    
3. Imposing in scale, scope, degree or power
   "massive retaliatory power"; "a massive increase in oil prices"; "massive changes"
    
4. Consisting of great mass; containing a great quantity of matter
   "Earth is the most massive of the terrestrial planets"

See also: big, heavy, large, solid

Encyclopedia: Massive