Notch/nɑːtʃ/ Definition 1 of 4Pro Tip 1/2Physical Mark Notch as a small cut often serves as a physical mark or indicator. The carpenter added a notch to the wood to mark where to cut. Pro Tip 2/2Measurable Progress Notches are used to track progress or count occurrences, like on a tally stick. The hiker marked a notch for every mile traveled.