What suffix is commonly used to denote a medical specialist?

The suffix commonly used to denote a medical specialist is -ologist. This suffix is derived from the Greek word "logia," meaning "study of" or "discourse," and is often appended to the root of a word to indicate a practitioner who specializes in a particular field of study or medicine. For instance, "cardiologist" refers to a doctor specializing in the study and treatment of heart conditions, while "psychologist" pertains to one who studies mental processes and behavior.

In contrast, the other suffixes provided have different meanings: -itis denotes inflammation, as seen in "arthritis," which is inflammation of the joints; -ectomy refers to the surgical removal of a specific part of the body, such as in "appendectomy," the removal of the appendix; and -pathy indicates disease or disorder, as seen in "neuropathy," referring to a disease affecting the nervous system. Each of these suffixes serves a unique purpose in medical terminology, but -ologist specifically identifies the role of a medical specialist.