Crown molding

Wall.svg
Diagram of a wall
  crown molding
  dado
A compound crown molding built up out of several individual trim elements
Decorative pilaster of natural cherry hardwood topped with crown molding
Crown molding may be a complex build-up of multiple trim elements, in this case built-out slightly above a window with short 90-degree returns
The relief on this short 90-degree return of crown molding was back-cut with a coping saw

Crown moulding (interchangeably spelled Crown molding in American English) is a form of cornice created out of decorative moulding installed atop an interior wall. It is also used atop doors, windows, pilasters and cabinets.

Historically made of plaster or wood, modern crown moulding installation may be of a single element, or a build-up of multiple components into a more elaborate whole.