When words or concepts are not understandable, it can create confusion or ambiguity. However, by identifying antonyms, it is possible to find alternative ways to communicate effectively. Some useful antonyms for "not understandable" could be "clear," "comprehensible," "intelligible," "transparent," "understandable," or "lucid." By using one of these antonyms, it is easier to convey a message or idea without any misinterpretation. Furthermore, finding antonyms can help expand one's vocabulary and make communication more precise, clear, and effective. Understanding antonyms can also be an excellent tool for language learners to enhance their comprehension skills, even when dealing with difficult or complex ideas.