Cloudcuckooland is a term used to describe an unrealistic or impractical idea or goal. There are several synonyms for this phrase including "fantasyland," "dreamland," and "utopia." Other synonyms include "never-never land," "la-la land," and "wonderland." These phrases all convey a sense of fanciful thinking or idealistic notions that may be disconnected from reality. Other terms that could be used as a synonym for cloudcuckooland might include "pipe dream," "naive concept," or "daydream." All of these expressions can be used to describe a situation or idea that is completely unattainable or unrealistic and offers little hope for success.