Noncommon is a word that is used to describe something as unusual, uncommon or rarely found. However, there are several synonyms that can be used for the word noncommon. Some of these include words like atypical, unusual, exceptional, extraordinary, unique, rare, uncommon or infrequent. Each of these synonyms carries a slightly different connotation and can be used in different contexts to convey a similar meaning to noncommon. For instance, if you're describing an object that is uncommon, you could say that it is atypical or unusual. Or, if you were describing a piece of art that is unique, you could say that it is exceptional or rare.