A monde, meaning 'world' in French, is an orb located near the top of a crown. It represents, as the name suggests, the world that the monarch rules. It is the point at which a crown's half arches meet. It is usually topped off either with a national or religious symbol, for example a cross in Christian countries.
Gallery
A monde and cross atop the crown of Pedro I of Brazil
St Edward's Crown (United Kingdom)
See also