Wiktionary
vb. To think deeply about; to ponder or mull over.
WordNet
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" [syn: think over, meditate, ponder, excogitate, contemplate, muse, reflect, mull, mull over, ruminate, speculate]
Usage examples of "chew over".
Robinton had a puzzle to chew over: T'kul's bitter words about the egg.
To ruminate is to chew over again what has been already swallowed.
Leaving his men to chew over that, Galen turned and continued on toward the keep.
He was a capable executive and could make rapid decisions when necessary, but he was by nature inclined to reserve his opinions when possible, until he had had time to chew over the data and assess it.
These seemed to be young bullocks for the most part, too thronged to lie down, but seemingly content enough with each other's warmth, and some dry fodder to chew over.