WordWeb Online

1. Extremeness of degree
   "the profoundness of his ignorance"
    
2. Wisdom that is recondite and abstruse and profound
   "the anthropologist was impressed by the profoundness of the native proverbs";
   - reconditeness, abstruseness, abstrusity, profundity
    
3. The intellectual ability to penetrate deeply into ideas
   - astuteness, profundity, depth, deepness
    
4. The quality of being physically deep
   - deepness, profundity
    
5. Intellectual depth; penetrating knowledge; keen insight; etc
   "the profoundness of the silence";
   - profundity

Type of: deepness, depth, sapience, ultimacy, ultimateness, wisdom

Antonym: shallowness