excogitate

(v) come up with (an idea, plan, explanation, theory, or principle) after a mental effort
- excogitate a way to measure the speed of light
devise, invent, contrive, formulate, forge,
(v) reflect deeply on a subject
- 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
chew over, meditate, mull, mull over, muse, ponder, think over, reflect, ruminate, speculate, contemplate,

devise invent contrive formulate forge chew over meditate mull mull over muse ponder think over reflect ruminate speculate contemplate