To reappear means to show up again after being gone or hidden. When a magician makes a rabbit disappear from a hat and then brings it back, the rabbit reappears. When the sun comes out after hiding behind clouds all morning, it reappears.

The word combines “re” (meaning again) with “appear” (to come into view). You might watch a character in a book disappear in one chapter and reappear mysteriously several chapters later. A lost toy might reappear weeks after you've given up looking for it, tucked behind the couch cushions.

Things can reappear physically, like when a friend walks back into the room, or they can reappear in more abstract ways: an old problem might reappear just when you thought you'd solved it, or a catchy song might reappear in your head days after you first heard it. The word suggests something familiar coming back, not something brand new arriving for the first time.