General Definition: 1. A visual deptiction using hands to represent a ball being encased by a rounded object and portraying the movement of the ball within the object. As a Noun: 1. The place in a machine where two parts of the machine (for example the wheels of a car) are connected to each other. The end of the first part is rounded and fits into a rounded space in the second part. English = ball joint. Note: 1. There appears to be no commonly used Auslan sign for BALL JOINT for most signers (but some signers represent this visually using depicting signs, once they have established the topic). If you know a sign for BALL JOINT used by you or other Auslan users (deaf people or interpreters) please go to "Report missing sign" and supply details. Thank you. 2. Source of this recommended sign: Victorian College for the Deaf