chew over
think over
meditate
ponder *
excogitate
contemplate **
muse *
reflect ****
mull
mull over
ruminate
speculate **

It meant the man was chewing over a heavy problem.

"She's been chewing over some information while we were talking."

And then we spend the rest of the day chewing over that.

I could see him chewing over my words, trying to make up his mind.

Most, it seems, would rather chew over their test scores.

So she watched from a well of growing indifference as the others chewed over the situation.

But after chewing over the idea, she took on the challenge.

Picking up my pace, I chewed over the situation one more time.

You think: He must have run into a former colleague, and they're chewing over the market.

They don't pop in to one another's officers to chew over some interesting idea.