The act of creating long, thin marks or lines on something.
Streakings can be intentional or accidental, and they can be seen as messy or artistic, depending on the context.
Examples:
She made streakings on the paper with her crayons.
The streakings on the wall were from the leaking roof.
I saw streakings of light coming through the window.
The cat made streakings in the wet paint.
The streakings on the canvas looked like a rainbow.
The streakings on the floor were from the muddy shoes.