To blow or sound a horn; to make similar noise by contact of the tongue with the root of the upper teeth at the beginning and end of the sound; also, to give forth such a sound, as a horn when blown
If someone toots their car horn or if a car horn toots, it produces a short sound or series of sounds. People set off fireworks and tooted their car horns Car horns toot as cyclists dart precariously through the traffic = hoot Toot is also a noun. The driver gave me a wave and a toot. if you toot your car horn, or if it toots, it makes a short high sound (From the sound). a short high sound made by a car horn