The word "dizening" refers to the act of dressing up or adorning oneself with fanciful clothing or accessories. While there are no direct antonyms for this word, there are several that can convey an opposite meaning. Words like "undressing," "disrobing," or "stripping" could indicate the opposite of dressing up or decorating oneself. Other antonyms could include "simplifying," "unfashionable," or "plain." Essentially, any word that conveys a more casual or simple appearance or demeanor could be considered an antonym for "dizening.