A rough drawing drawn without a scale is called a sketch.
A sketch is usually a quick and informal representation of an idea or concept. Artists and designers often use sketches to explore different facets of their projects without getting bogged down in details. Because sketches lack precise measurements and are drawn without a specific scale, they allow for flexibility and spontaneity during the creative process.
In summary, sketches serve as valuable tools for brainstorming and conceptualization, providing a visual reference that can be developed further into more detailed and scaled drawings if needed.