Mulls (over) is a term that means to think deeply about something. Chews (5 letters) is an action that involves biting and grinding food in the mouth. Ponder (7 letters) is to consider something carefully and thoughtfully. Muse (5 letters) is to be lost in thought or to contemplate something. Peruse (7 letters) is to read or examine something carefully. All of these terms can be used to describe the action of mulling over something, which is to think deeply and carefully about it.