what is specialist
Definition of specialist for English Language Learners. : 1  a person who has special knowledge and skill relating to a particular job, area of study, etc. : 2  a doctor who deals with health problems that relate to a specific area of medicine. : 3  a rank in the U.S. Army that is above the rank of private and below the rank of corporal.
A specialist in pathology; a physician who performs, interprets, or supervises diagnostic tests, using materials removed from living or dead patients, and functions as a laboratory consultant to clinicians, or who conducts experiments or other investigations to determine the causes or nature of disease changes.