This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Becoming professional in the use of something; having mastery of

v. Present participle of master.

n. becoming proficient in the use of something; having mastery of

n. the act of making a master recording from which copies can be made

"Learning correct liaison is one of the challenges in mastering French."

important    of import   

mastered    mastering    masters   

scholarly person    student    bookman    scholar    creation    know   

master in chancery    master workman    master of the mint    in glomery    master of misrule    master passion    master in lunacy    master of the sentences    the master    master's mate   

captain   

own    posses    excel    long shot    establishing shot    skipper    captain    masters    master's   

Astor    Castor    Grandmaster    aster    blaster    caster    castor    disaster    faster    gaster   

father    king    lady    officer    teacher    chief    doctor    author    fellow    servant