The word junked-up, according to its definition, means cluttered or untidy. Its antonyms, therefore, would be words that signify or describe cleanliness and neatness. Words such as organized, tidied, arranged, ordered, or systematic are all great antonyms for this word. When you use these words, you communicate exactly the opposite of junked-up, and instead, convey an environment or space that is clean and well-maintained. Whether you're describing a room, a home, an office, or a workspace, using antonyms for the word junked-up can help you create a clear and concise picture of the environment you're describing.