ponder
v.v. to think about something carefully for a long time before you make a decision.
v. to weigh a matter in the mind with thoroughness and care. Often implies a slow, deliberate mental process rather than a quick thought.
I need some time to ponder your suggestion.
She sat by the window for hours to ponder whether she should accept the job offer in another city.
As the philosopher walked through the gardens, he began to ponder the relationship between human consciousness and the natural world, eventually filling several notebooks with his observations.
From Middle English ponderen, from Old French ponderer (“to weigh, balance, ponder”) from Latin ponderāre (“to weigh, ponder”), from pondus (“weight”), from pendere (“to weigh”); see pendent and pound.
The verb can be used transitively with a direct object or intransitively followed by 'on' or 'over'.
I pondered about the problemI pondered the problemWhile 'ponder on' or 'ponder over' are common, 'ponder about' is generally considered incorrect; the verb is most often used transitively.