Customer (noun)

1. A person who buys goods or services from a shop or business.
2. A person or organization that uses the services of a professional or company.
3. A person or organization that receives or is intended to receive an item or service.
4. A person or organization that is provided with a service or product by another.
5. A client, as of a professional person or company.

Origin:

From middle english custumer, from old french client, from latin clientem ("customer, client"), from cliēns ("follower, dependant"), from cliēre ("to lean, inclin.e")

Examples:

1. The customer is always right.
2. He has been a loyal customer for many years.
3. The store had a steady stream of customers.
4. The service is tailored to meet the needs of each customer.
5. The customer service representative was able to assist me with my inquiry.