Specialist

n. one who limits himself to a particular profession or field of study; physician who specializes in a particular branch of medicine; enlisted person having specific expertise and ranking above private (U.S. Military)

adj. characterized by adherence to a particular profession or field of study

Specialist frequently refers to an expert in a profession. It can also mean:Specialist (rank), a military rankSpecialist degree, in academia"Specialist", a song by the band Interpol"The Specialist", the English translation of "Lo Sconosciuto", an Italian comics characterGeneralist and specialist species, a method of species categorizationA market maker in a stock exchangeMedical specialist, someone who specializes in a particular field of medicinePayload Specialist, a Space Shuttle crewmember selected for a single specific mission
See more at Wikipedia.org...

Noun
1. an expert who is devoted to one occupation or branch of learning
(synonym) specializer, specialiser
(antonym) Renaissance man, generalist
(hypernym) expert
(hyponym) enologist, oenologist, fermentologist
(derivation) specialize, specialise
2. practices one branch of medicine
(synonym) medical specialist
(hypernym) doctor, doc, physician, MD, Dr., medico
(hyponym) anesthesiologist, anesthetist, anaesthetist
(derivation) specialize, specialise

n. specialist

(n.)
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.