黒い絵（くろいえ、スペイン語: Pinturas negras）とは、スペインの画家フランシスコ・デ・ゴヤが、晩年に自身の住居の部屋の壁に描いた一連の絵画の総称。
In set theory and its applications throughout mathematics, a class is a collection of sets that can be unambiguously defined by a property that all its members share.