The word "fatheads" is a colloquial term used to describe foolish or stupid people. Antonyms for this word would be those that describe intelligent, clever or wise individuals. For example, words like astute, shrewd, brilliant, knowledgeable and well-informed would be antonyms for "fatheads". Other antonyms could include adjectives like perceptive, sharp, insightful, and discerning. These qualities are often associated with individuals who are able to grasp complex ideas, think critically and solve problems effectively. Therefore, if someone wants to praise intelligence or wit, using antonyms for "fatheads" could be a good way to do so.