1. Penetrating or entering deeply into subjects of thought or knowledge; having deep insight or understanding: A profound thinker.
2. Originating in or penetrating to the depths of one's being; profound grief.
3. Being or going far beneath what is superficial, external, or obvious: Profound insight.
4. Of deep meaning; of great and broadly inclusive significance: A profound book.
5. Pervasive or intense; thorough; complete: A profound silence.
6. Extending, situated, or originating far down, or far beneath the surface: The profound depths of the ocean.