chew over, cogitate, consider, contemplate, debate, deliberate, entertain, eye, kick around, meditate, mull (over), ponder, pore (over), question, revolve, ruminate, study, think (about or over), turn, weigh, wrestle (with)

muse (upon), reflect (on or upon), reminisceanalyze, explore, reviewconclude, reasonsecond-guess, speculate (about)brood (about or over), dwell (on or upon), fixate (on or upon), fret (about or over), obsess (about or over)believe, conceive, opineabsorb, assimilate, digest, drink (in)

beat one's brains out (about), chew on, cudgel one's brains (about), look at