Oxo- is a prefix that is commonly used in the field of chemistry to describe compounds that contain an oxygen atom bonded to a carbon atom by a double bond. However, there are several synonyms for the word "oxo-" that are also used in chemistry, such as "keto-", "aldehydo-", and "formyl-". These prefixes are used to describe specific chemical compounds that contain different functional groups, such as ketones, aldehydes, and formyl groups. By using these synonyms, chemists can more precisely describe the structure and properties of different compounds, helping to improve our understanding of the complex chemical world around us.