Catenulate means having a chain-like appearance or arrangement. Therefore, some possible antonyms for catenulate could be words that describe objects or structures that are not connected in a linear or sequential manner. For example, words like dispersed, scattered, disconnected, or disorganized. These words suggest a lack of continuity or cohesion, and instead indicate a random or unordered arrangement. Other antonyms for catenulate could be words that imply a simple or singular shape, such as round or smooth, as opposed to the complex and elongated shape associated with catenulate structures. Ultimately, the choice of antonym will depend on the context in which the word is being used.