A more thorough explanation:

Definition: Held in common by two or more persons or things.

Some examples of the term "joint" in a legal sense include:

• Joint custody: An arrangement in which both parents have legal or physical custody of a child or children after a divorce or separation.
• Joint defendant: A defendant involved in a lawsuit with two or more defendants.
• Joint liability: Liability that is shared by two or more defendants due to their shared responsibility for a debt, claim, or judgment.
• Joint ownership: An arrangement in which each owner has an undivided interest in property, usually with a right of survivorship. For example, if two people own a house jointly and one person dies, the other person automatically becomes the sole owner of the house.
• Joint tortfeasors: Two or more defendants whose negligence contributed to the plaintiff's injuries and are thus jointly liable for damages in the same lawsuit.

These examples illustrate the definition of "joint" because they all involve two or more people or things sharing something in common. In joint custody, both parents share custody of their child. In joint ownership, both owners share an interest in the property. In joint liability, multiple defendants share responsibility for a debt or claim. And in joint tortfeasors, multiple defendants share liability for the plaintiff's injuries.