The term does not do anything! In simple term, it means a solid. It may be defined in terms of its length, width and height (the 3 dimensions).
Faces are a term used in Geometry to describe a side on a three-dimensional figure
A solid is a 3 dimensional object in terms of math.
Proprioception is the medical term meaning three-dimensional perception.
trompe l'oeil
Trompe L'oeil, maybe, though it's not really related to the Math, Algebra, Geometry category.
Having three sides.
three dimensional
"3D"
They are solid shapes as for example a pyramid
Cubic
Solid shaper: ones that have a length, width and depth.
Perspective, perhaps.