One who devotes himself to some specialty; as, a medical specialist, one who devotes himself to diseases of particular parts of the body, as the eye, the ear, the nerves, etc.
- One who is devoted to a particular occupation or branch of study or research: "Specialists . . . tend to think in grooves” ( Elaine Morgan).
- A physician whose practice is limited to a particular branch of medicine or surgery, especially one who is certified by a board of physicians: a specialist in oncology.
- Any of several noncommissioned ranks in the U.S. Army that correspond to that of corporal through sergeant first class.