Dingdong is the sound a doorbell or large bell makes: a two-note chime that goes “ding” (high) then “dong” (low). When someone rings your doorbell, you hear that familiar dingdong echoing through the house, letting you know a visitor has arrived.

The word imitates the actual sound, which linguists call onomatopoeia. Big bells, like church bells or clock tower bells, make a similar two-tone sound as they swing back and forth, the clapper striking different sides of the bell. Smaller doorbells create the same effect electronically or with two different metal chimes.

As an interjection, dingdong! can be used to imitate a doorbell sound, especially in stories or jokes.

You might also hear dingdong used playfully to describe an ongoing back-and-forth, like a dingdong battle in sports where neither team can pull ahead. The word captures that alternating, back-and-forth rhythm, just like the doorbell's two notes.

In older books and stories, you'll sometimes see “ding-dong” written with a hyphen, but both spellings mean the same thing: that cheerful, familiar sound that announces someone at your door.