mastery

1 a highly developed skill in or knowledge of something the exchange student returned from her year in Spain with a complete mastery of the language Synonyms IQ, mastership, command, proficiencyRelated Words virtuosity; facility, hang; fluency, literacy; experience, expertise, know-how, practice (also practise), skill(s); acquaintance, familiarity, intimacyNear Antonyms incompetence, incompetency; ignorance, illiteracy, unfamiliarity

2 the right or means to command or control others the British monarch has only token mastery over the citizens of the United Kingdom Synonyms arm, authority, clutch, command, control, death grip, dominion, grip, hold, power, reign, rein(s), swayRelated Words clout, influence, leverage, pull, voice, weight; jurisdiction; direction, management; dominance, imperium, predominance, sovereignty (also sovranty), supremacy; prerogative, privilege, right; eminence, importance, momentNear Antonyms helplessness, weaknessAntonyms impotence, impotency, powerlessness