Feeble-minded is a word used to describe someone who is mentally weak or deficient. Some antonyms for this word are intelligent, genial, clever, bright, smart, and quick-witted. Intelligent refers to someone who possesses a high level of cognitive ability, which enables them to understand concepts easily. Clever means possessing a sharp mind and thinking quickly, and bright refers to someone who is quick to understand and learn things. Similarly, someone who is smart has a quick intellect and can use it to solve problems effectively. Lastly, quick-witted refers to someone who is mentally sharp and can think on their feet, making them quick to respond to different situations.