The term 'Impossible Dream' is a phrase that has been used to describe an unattainable goal or ambition. The two crossword solutions for this term are 'CHIMERA' (7 letters) and 'Castleintheair' (14 letters). CHIMERA is a mythical creature composed of parts from multiple animals, and is often used to symbolize an impossible dream. Castleintheair is a phrase that refers to something that is not real or attainable, and is also used to describe an impossible dream.