Final answer:
The term that best defines a professional etiquette in which a primary clinician refers a case to a specialist for further diagnosis and treatment is referral.
Step-by-step explanation:
The term that best defines a professional etiquette in which a primary clinician refers a case to a specialist for further diagnosis and treatment is referral.
A referral is when a primary clinician determines that a patient would benefit from the expertise of a specialist and sends the patient to that specialist for a specific evaluation or treatment. It is a common practice in the medical field to ensure that patients receive the most appropriate and specialized care for their specific condition.
For example, if a patient presents with a complex cardiac issue, the primary clinician may refer them to a cardiologist for further evaluation and treatment.