The antonyms for the word "more percipient" are less aware, less discerning, less sensitive, and less observant. Someone who is less aware is not paying attention to their surroundings or is not mindful of their environment. Similarly, someone who is less discerning lacks the ability to judge or distinguish between different things or situations. A less sensitive person lacks empathy or the ability to perceive other people's feelings or emotions. Lastly, a less observant person is not paying attention to the details or the changes happening around them. These antonyms highlight the importance of being perceptive and aware of one's surroundings to get a better understanding of the world around us.