The phrase "move to fro" can be synonymous with "rock back and forth," "swing," "sway," "oscillate," "bob," "toss," "jiggle," "wobble," and "flutter." These words all describe a back-and-forth motion, whether it's in a linear or circular pattern. The context in which the phrase is used will determine which synonym is best suited to convey the intended movement. For example, "jiggle" might be appropriate when describing a loose object shaking slightly, while "sway" would work better for a tree moving gently in the wind. Adjectives can also be added to further describe the motion, such as "rapidly jiggle" or "slowly sway".