If you are cogitating, you are thinking deeply about something. [formal]
He sat silently cogitating. [VERB]
...to cogitate on the meaning of life. [V + on/about]
Synonyms: think, consider, reflect, contemplate
cogitation (kɒdʒɪteɪʃən ) uncountable noun After much cogitation, we decided to move to the Isle of Wight.
Synonyms: thought, consideration, reflection, meditation