repoussoir
/rɪˈpuːswɑː/noun
1 Painting. An object in the foreground of a composition (typically to one side), which serves to lead the viewer's eye into the principal scene or towards the principal figure, emphasizing this and increasing the sense of depth.
2In extended use and figurative.
Origin
Mid 19th century (in an earlier sense). From French repoussoir from repousser + -oir.