What Does CC mean on a motorcycle?

On a motorcycle, CC or cubic centimeters refers to engine capacity. Specifically it refers to the amount of air/fuel mixture able to fit into the cylinders (where combustion occurs) at full expansion. 1 cc is equivalent to 1 gram of water aka 1 ml. An example: 250 cc engine means the cylinders with pistons at full expansion can hold a volume of 250 ml of air/fuel mixture prior to the combustion stroke.

In all vehicles, atleast I think, it stands for cubic centimeters
It's the total capacity of the cylinder(s) in cubic centimetres
"CC" means "Cubic Centimeters" which is common engine size measurement for motorcycles.

MCg

Motorcycle-Intelligence.com
I assume you mean what the typical engine size of a motorcycle is?

If so, it has a rather big range.

Small motorcycles usually can be categorized from 50-250cc

Medium size are usually 250-500CC

Larger motorcycles have engine sizes from 600-1800 depending on their category (sport,custom,supermotard, dirt bike)
Cubic centimeter.