Ponder over is a phrase that means to think deeply about something. The crossword solutions for this phrase are MULL, PORE, and dwellon. MULL is a verb meaning to think deeply or reflect on something, while PORE is another verb meaning to read or study something carefully. Dwellon is a verb meaning to think or meditate on something for a long period of time. All three words can be used to describe the act of pondering over something.