The term "decompound" refers to the process of breaking down a chemical compound into simpler substances. The opposite of decompound would be to compound, which means to combine two or more elements or compounds to form a larger and more complex substance. Other antonyms for decompound could include assemble, integrate, join, unite, or amalgamate. In the context of language, an antonym for decompound might be to compound words, which involves combining two or more words to create a new one, such as "blueberry" or "lighthouse." Another possible antonym for decompound could be to simplify or streamline, which involves reducing something to its essential components or making it more accessible and easier to understand.