Referral (noun)

1. The act of referring someone or something to another person or place.
2. A recommendation or introduction to a person or organization.

Origin:

From old french referer, from latin referre "refer".

Examples:

1. He received a referral from his friend for a job opportunity.
2. The patient was given a referral to a specialist for further treatment.
3. The company's success is largely due to the referral business it receives.
4. She gave me a referral for a good mechanic.
5. The doctor gave a referral for a physical therapy.