One antonym for the word "re-flex" is "slow." A slow response would be the opposite of a quick, automatic reaction. Another antonym is "stagnant," which suggests a lack of movement or change. If someone's reflexes are stagnant, they may be unable to respond quickly to unexpected situations. "Hesitant" is another antonym, suggesting a reluctance or delay in reacting to a stimulus. Conversely, "instinctive" is a synonym for "re-flex," and indicates an immediate and automatic response without conscious thought. Overall, antonyms for "re-flex" have a common theme of slowness, hesitation, and lack of automaticity.