The term 'uncommon thing' can be described by three different crossword solutions: RARITY (6 letters), ODDITY (6 letters), and raravais (8 letters). RARITY is defined as something that is not common or usual, and is often associated with being valuable or rare. ODDITY is defined as something that is strange or unusual, and is often associated with being out of the ordinary. Raravais is a French word meaning something that is rare or uncommon. All three words describe something that is not commonly found or seen.