Meaning of the phrase dog-eared

Answer 1

When you use dog-eared as a noun, it means turning down the corner on a page in a book. It would resemble the ears on a dog that stand up then the upper portion folds down.

As a verb - it means - to turn down a corner (eg the page of a book) or to make worn or shabby from overuse

Answer 2

Worn or shabby from overuse (of pages), or from having corners turned down; "a somewhat dog-eared duke...a bit run down"-Clifton Fadiman; "an old book with dog-eared pages"

To be bent or slightly ragged in appearance in a manner like the ear of certain dogs. It implies that the page has been read a lot, but could be a sign of mistreatment; to be folded in a manner like the ear of certain dogs. It implies the page was purposely folded to mark the page.

Book pages which have been folded over in the corners. Some people do this to mark their place in a book.

It's bad for books, please don't do it.