The word "most chatoyant" refers to something that has a lustrous, shining quality. Antonyms for this word include dull, flat, and unremarkable. If something is dull, it lacks the brilliance and sparkle associated with chatoyancy. A flat object is devoid of any depth or dimension, making it impossible for it to exhibit the chatoyant quality. Finally, an unremarkable thing is simply not noteworthy, and would not be able to capture anyone's attention in the way that something chatoyant would. Therefore, when searching for antonyms for the word "most chatoyant," look for words that describe something that is not bright, shiny, or captivating.