cogitation

/ˌkɑdʒɪˈteɪʃən/
noun
  1. The act of thinking deeply and carefully; serious thought.
    • He sat in deep cogitation, unaware of the noise around him.
    • After much cogitation, she finally solved the math problem.
    • The scientist's cogitation led to a major breakthrough in physics.
Synonyms
What does "cogitation" mean? | whatsthatwordmean | whatsthatwordmean