Rutilant is a term used to describe something that glows or shines with a reddish glow. It is derived from the Latin word 'rutilus', meaning reddish or ruddy. The antonyms of rutilant are words that describe the absence of this quality. Words like dull, dim, and lackluster can be considered as antonyms of rutilant. These words are used to describe something that lacks brightness or shine. Conversely, words like vibrant, radiant, and sparkling can be considered as synonyms of rutilant. These words describe something that glows or shines with a bright and vibrant quality. Antonyms and synonyms are useful tools to build vocabulary and aid in effective communication.