Scratch means to scrape or rub something with something sharp, like fingernails or claws. When a mosquito bite itches, you might scratch it with your fingernails to get relief. A cat scratches furniture with its claws, which is why people buy scratching posts. You can scratch an itch, scratch your head when you're confused, or accidentally scratch your knee on a rough surface.

The word also describes the mark left behind by scratching. A scratch on a wooden desk is a thin line where something scraped away the finish. Your phone screen might get scratches from being in your pocket with your keys. A small cut or scrape on your skin is called a scratch too, like when a branch scratches your arm during a hike.

When you start from scratch, you begin at the very beginning with nothing prepared, like baking cookies from scratch instead of using pre-made dough. If you scratch someone from a list, you cross their name out. A scratch golfer plays at par, needing no handicap advantage. And when something barely begins to deal with a problem, people say it only scratches the surface.