The term 'EXTREMELY FOOLISH' can be described by four different words, all of which have seven or fewer letters. The first word is 'MORONIC', which means 'stupid or foolish'. The second word is 'ASININE', which means 'extremely silly or stupid'. The third word is 'LOONY', which is a slang term for 'CRAZY'. The fourth and final word is 'INSANE', which means 'mentally ill or irrational'. All of these words are used to describe someone who is extremely foolish.