expert

(noun) a person with special knowledge or ability who performs skillfully.

(adj) having or showing knowledge and skill and aptitude. Synonyms: adept, good, practiced, proficient, skillful, skilful. Examples: "Adept in handicrafts." "An adept juggler." "An expert job." "A good mechanic." "A practiced marksman." "A proficient engineer." "A lesser-known but no less skillful composer." "The effect was achieved by skillful retouching."

(adj) of or relating to or requiring special knowledge to be understood. Synonyms: technical. Examples: "Technical terminology." "A technical report." "Technical language."