The unlawful restriction of a client's freedom of movement is called:

Defamation refers to a false statement that injures a person's reputation. It involves the communication of harmful information to a third party and does not pertain to the restriction of freedom of movement. Therefore, defamation does not relate to the unlawful confinement of an individual.

Negligence involves a failure to exercise appropriate care, resulting in harm to another person. While negligence can lead to various legal claims, it does not directly address the concept of restricting someone's freedom. Thus, negligence is not relevant to the definition provided in the question.

Invasion of privacy pertains to the violation of an individual's right to keep their personal life private. It involves unauthorized access or disclosure of personal information rather than the physical restriction of movement. Therefore, it does not accurately describe the unlawful confinement of a person.