mull

[1]	mull over , ponder , consider , study , think (over/about) , cogitate (on/over/about) , con , evaluate , turn over , weigh , deliberate (on/over) , reflect (on) , muse (on) , review , examine , contemplate , meditate (on) , chew over , ruminate (on/over)
[2]	chew over , think over , meditate , ponder , excogitate , contemplate , muse , reflect , mull over , ruminate , speculate