profound

/prəˈfaʊnd/
adjective
  1. Very great or intense; having a strong effect.
    • He felt a profound sense of loss after his dog died.
    • The discovery led to profound changes in medicine.
    • The news had a profound impact on her life.
  2. Showing great knowledge or deep understanding.
    • The professor gave a profound lecture on human nature.
    • He is known for his profound thoughts about the meaning of life.
    • Her book offers profound insights into the history of art.
  3. Very deep or extreme (used especially of sleep, silence, or feelings).
    • He expressed profound gratitude to his teachers.
    • She fell into a profound sleep after the long hike.
    • The forest was filled with a profound silence.