The antonyms for the word "untidiest" are neat, tidy, clean, orderly, and prim. These words denote a sense of positive cleanliness and organization, signifying a well-kept and well-maintained space. A neat and tidy environment promotes productivity and encourages a sense of calm for individuals. A clean and orderly space ensures a hygienic and healthier living atmosphere, free from dirt and clutter. Prim surroundings denote a polished and refined sense of organization, portraying a high-level decorum, and aesthetic appeal. Therefore, incorporating these antonyms into one's life can have a substantial positive impact on an individual's physical and mental well-being.