Empty-headedness refers to the state of being stupid, foolish or ignorant. Its antonyms or opposite words include intellect, intelligence, wisdom, sagacity, acumen, astuteness, and insightfulness. With these opposing words, empty-headedness can be replaced with words that imply or describe intelligence, wit, and sharpness of the mind. Intellect involves the ability to understand complex ideas and use critical thinking. Intelligence refers to the potential to learn, reason, and apply knowledge to solve problems. Wisdom is characterized by deep insight and sound judgement based on experience and knowledge of life. Sagacity, on the other hand, is the ability to discern and make good judgements in uncertain situations, while acumen is the sharpness or skill in perception and understanding.