Chuckle-headed is an informal term used to describe someone who is foolish or unintelligent. There are many synonyms you can use to describe someone in this way, such as dimwitted, dense, blockheaded, thickheaded, or obtuse. These words all suggest a lack of intelligence or common sense. Other synonyms include knucklehead, bonehead, and numskull, which are often used affectionately to describe someone who is not particularly bright. However, it's important to remember to use these words with caution, as they can be considered insulting or derogatory. It's always better to choose your words carefully when describing someone's intelligence or lack thereof.