Freebase(0.00 / 0 votes)Rate this definition: Crayon. A crayon is a stick of colored wax, charcoal, chalk or other material. A crayon made of oiled chalk is called an oil pastel; when made of pigment with a dry binder, it is simply a pastel. A grease pencil or china marker is made of colored hardened grease. There are also watercolour crayons, sometimes called watersoluble crayons.