triptych       
noun [ C ]  art specialized uk/ˈtrɪp.tɪk/ us/ˈtrɪp.tɪk/
 三幅相联的图画
a piece of art made of three paintings connected to each other in a way that allows the two outer ones to fold in towards the larger central one
  A medieval triptych hung above the altar. 一幅中世纪的三联画挂在祭坛上方。