Silhouette
The flattened outline of a volumetric object, shown without internal depth, detail, or texture.
In practice
A silhouette is a three-dimensional object reduced to its flat outline, filled solid, with no internal detail. It tests whether a shape is recognizable at a glance, which matters for icons, characters and products. A well-designed bottle can be identified from its silhouette alone, and a game character is often refined until its solid black outline is distinct from every other character's.
Often confused with Form
A silhouette is only the flat outline of an object; form includes its full three-dimensional shape and structure.
Try this
Fill the outlines of five household objects with solid black and ask someone to name each one.