Dog-eared describes the worn, folded-down corners of book pages that happen when readers mark their place by bending the page instead of using a bookmark. If you've ever grabbed the top corner of a page, folded it down into a little triangle, and closed the book, you've dog-eared it. The name comes from how those bent corners look a bit like a dog's floppy ear.

A well-loved book often becomes dog-eared over time, with creased corners throughout marking favorite passages or interesting spots. You might find a dog-eared cookbook in your grandmother's kitchen, with turned-down corners on the recipes she makes most often. Libraries usually ask people not to dog-ear their books, since those bent corners are hard to flatten back out and the damage adds up as books pass through many readers' hands.

The word can describe anything worn or shabby from heavy use. A dog-eared map has been folded and unfolded so many times that its creases are soft and torn. A dog-eared notebook has seen months of being stuffed into backpacks and pulled back out. When something becomes dog-eared, it shows the marks of being genuinely used and needed.