The term 'as a fiddle' is an idiom that means to be in perfect condition. The two crossword solutions for this term are FIT (3 letters) and ASFIT (5 letters). FIT is an acronym for 'Fully In Tune', which is a phrase used to describe something that is in perfect condition. ASFIT is an acronym for 'As Sound as a Fiddle', which is another phrase used to describe something that is in perfect condition.