Onto- is a prefix that means "on top of" or "upon". It is commonly used in the English language to convey the sense of a transition from one state to another. There are several synonyms for onto-, such as "upon", "above", "over", "atop", "on", "upon the surface of", "on top of", "on the top side of", "on the upper surface of", "at or to a point on (something)", "on the surface of", "on the exterior of", "upon the exterior of", and "covering". By using these alternatives, writers can create a more diverse and nuanced language, thus enriching their texts.