Making plain means to clarify or make something clear. Antonyms for this phrase include words that denote confusion, obfuscation or complexity. Words such as mystifying, muddling, complicating, baffling, obscuring, and confounding, are antonyms for making plain. These words suggest that an idea or message is not being conveyed clearly or that the speaker or writer is intentionally obscuring the meaning. When trying to communicate effectively, it is important to avoid using antonyms of making plain and to strive for clarity and simplicity to ensure that your ideas are understood by your audience.