When it comes to discussing an issue or idea, we often use the phrase "chew on" to describe the act of thinking about it. However, there are several other synonyms that can be used to convey the same message. One such synonym is "ponder," which means to think deeply about something. Another option is "mull over," which suggests a more methodical and deliberate consideration. "Contemplate" also works well, indicating a more serious and thoughtful process of reflection. Other synonyms include "cogitate," "ruminate," and "meditate on." Ultimately, the choice of synonym will depend on the specific context and the tone that the speaker wishes to convey.