The state of being completely clean and without any spots or marks.
Spotlessness is usually seen as a good thing, like when something is very clean and looks nice.
Examples:
The spotlessness of the kitchen was impressive.
She takes pride in the spotlessness of her car.
The spotlessness of the white dress was ruined when she spilled juice on it.
The spotlessness of the snow made everything look bright and pretty.
The spotlessness of the room was so perfect, it looked like no one had ever been there.
The spotlessness of the mirror made her reflection look extra clear.