Meaning : Look at thoughtfully. Observe deep in thought.
Example :
Contemplate one's navel.
Meaning : Consider as a possibility.
Example :
I contemplated leaving school and taking a full-time job.
Meaning : Reflect deeply on a subject.
Example :
I mulled over the events of the afternoon.
Philosophers have speculated on the question of God for thousands of years.
The scientist must stop to observe and start to excogitate.
Synonyms : chew over, excogitate, meditate, mull, mull over, muse, ponder, reflect, ruminate, speculate, think over