размышлять

1) General subject: brood (особ. грустно), cerebrate, chew, cogitate, consider, contemplate, deliberate, intellectualize, meditate, meditate (on, upon), mull over, muse, muse (about, on, over, upon), ponder, ponder (on, over), ponder over, ponder over (о чем-л.), pore, reason, reflect, reflect (часто on, upon), revolve, ruminate, see, speculate, study, think, ponder on, ponder over, brood about, brood on, brood over, brood upon

2) American: excogitate, mull

3) Obsolete: bethink, perpend

4) Psychology: ratiocinate

5) Jargon: kick (something) around

6) Business: debate, peruse

7) Psychoanalysis: doctrinize

8) Makarov: chew on, chew the cud, chew upon

9) Scuba diving: figure out