Constructive possession refers to a legal concept where a person does not have physical control over an item but has the ability to exercise control over it. This means that even if someone is not holding or directly using an item, they can still be considered to possess it if they have the power to access or control it. For example, if a person has a key to a safe containing drugs, they may be charged with possession of those drugs even if they are not physically present with them. Constructive possession is often used in legal cases to establish ownership or responsibility for items that may be illegal or regulated.