Definition: (1) fully accomplished in an art, science, or career; (2) having great knowledge and experience in a trade or profession

Derivation: Latin, “to go forward”

Synonyms: Proficient implies a thorough competence derived from training and practice; adept implies special aptitude as well as proficiency; expert implies extraordinary proficiency and often connotes knowledge as well as technical skill; skilled stresses mastery of technique; skillful implies individual dexterity in execution or performance.