The phrase "to chew over" means to think deeply and carefully about something, often for a long period of time. It is an idiomatic expression that implies giving serious consideration or contemplation to an issue, problem, idea, or plan in order to arrive at the best possible solution or decision. The term comes from the physical act of chewing food slowly and thoroughly before swallowing it, which allows for proper digestion and absorption of nutrients. In a similar way, "chewing over" something mentally helps to fully understand and process information before making a final judgment or taking action.