fishtailPronunciation: /ˈfɪʃteɪl/Definition of fishtail noun 1 [usually as modifier] an object which is forked like a fish’s tail:fishtail battlements 2an uncontrolled sideways movement of the back of a motor vehicle:he hit the brake, sending the car into a fishtail that carried him across the street verb [no object, usually with adverbial of direction] (of a vehicle) make an uncontrolled sideways movement:the vehicle fishtailed from one side of the road to the otherfishtail in other Oxford dictionaries Definition of fishtail in the US English dictionary