a person or organization using the services of a lawyer or other professional person or company.
insurance tailor-made to a client's specific requirements
(in a network) a desktop computer or workstation that is capable of obtaining information and applications from a server.
Users and even integrators will disagree with where lines are drawn between PCs, servers, thin clients , and workstations.
(in ancient Rome) a plebeian under the protection of a patrician.
In ancient Rome clients were plebeians who were bound in a subservient relationship with their patrician patron.