A solid cannot be bounded by one polygon. A solid bounded by polygons is called a polyhedron.
If the octagon is a regular octagon (all eight sides and all eight angles are equal), then it is a regular polygon. If it is not a regular octagon (i.e. if it is an irregular octagon) then is it an irregular polygon.
A regular octagon has 8 sides.
An 8 sided octagon can be either regular or irregular in shape.
A polygon with eight sides, regular or not, is an octagon. There isn't a special name for a regular octagon (other than "regular octagon").
A regular octagon has 8 sides similarly to an octagon. The name regular octagon means that all angles are the same, therefore inferring that all sides are of equal length.
A octagon is a octagon without the same angles as the others.
A regular prism.
In a regular octagon, each angle is 135 degrees. If the octagon is not regular, then it can have as many as 6 right angles in it.
A regular octagon will not tessellate but an irregular one can.
A regular octagon will not tessellate but an irregular one can.
A regular octagon will not tessellate but an irregular one can.