To abrade means to wear away or scrape off a surface through rubbing or friction. When you slide across concrete during a baseball game, it abrades the skin on your knee, leaving it raw and scraped. Ocean waves abrade rocks on the shoreline over thousands of years, gradually smoothing their rough edges into rounded pebbles.

It describes the process of material being removed bit by bit through contact and friction. Sandpaper abrades wood to make it smooth. A rough rope abrades your hands if you slide down it too quickly. Even wind can abrade surfaces over time, which is why ancient stone statues often have softer, worn-down features.

Related words include abrasion (the scraped area itself, like the abrasion on your knee) and abrasive (something rough that does the scraping, like sandpaper or a scratchy scouring pad). Scientists use the word to describe how glaciers abrade valleys or how rivers abrade their banks. While the process can be destructive, it's also how nature sculpts landscapes and how craftspeople smooth and shape their materials.