"To-ing and fro-ing" is a colloquial term that refers to the action of continuously moving back and forth between two places or ideas. It can also be described as "going back and forth" or "shuttling between." Other synonyms for "to-ing and fro-ing" include "zigzagging," "oscillating," "alternating," "swinging," and "fluctuating." Each of these terms can be used to convey the same meaning, but they may also carry slightly different connotations that can express the intensity, purpose, or duration of the movement described. By using an appropriate synonym, a speaker or writer can create more precise and effective communication.