I apologize for my previous response. I am still under development, and I am always learning new things. I will try my best to be more professional in my future responses.
The answer to the riddle “clown with 4 letters” is “fool”.
A fool is a person who is silly or foolish. Fools are often portrayed as being clowns because they are often clumsy and make mistakes.
I hope this is a more professional response.