The term NOT SO can be represented by four different crossword solutions: FALSE (5 letters), UNTRUE (6 letters), LESS (4 letters), ITSALIE (7 letters), and THATSALIE (9 letters). FALSE and UNTRUE are synonyms for each other, meaning not true or incorrect. LESS is a comparative form of the word 'LITTLE' and can be used to describe something that is not as much as it could be. ITSALIE and THATSALIE are both anagrams of the phrase 'it's a lie', which is another way of saying something is not true.