The antonyms for the word "leave plain" suggest enhancing, embellishing or decorating something. The opposite terms include: beautify, adorn, enrich, ornament, embellish, decorate, aggrandize, enrich, improve, mutate, sophisticated, and refine. These terms indicate the process of improving or refining something, making it more appealing or visually attractive. For instance, embellishing a dress can turn a simple design into something elegant and fancy. Decorating a room can transform a plain space into an extraordinary ambiance. The antonyms for "leave plain" emphasize the importance of creativity and innovation in making something unique and impressive.