come up with (an idea, plan, explanation, theory, or principle) after a mental effort; excogitate a way to measure the speed of light

[ Syn: invent , contrive , devise , formulate , forge ]

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

[ Syn: chew over , think over , meditate , ponder , contemplate , muse , reflect , mull , mull over , ruminate , speculate ]