notch
Definitions
A V-shaped indentation or cut on an edge or surface.
A level or degree in a scale or ranking.
To make a V-shaped cut or incision in something.
Examples
He carved a small notch into the wooden post to mark his progress.
The team's performance moved up a notch after the coach gave them a pep talk.
She adjusted the belt to the next notch because it was feeling a bit loose.