Be on top of

• Deal with successfully
• Be or become completely proficient or skilled in
• Have a firm understanding or knowledge of
• Have dominance or the power to defeat over
• Get on top of

WordNet Word definitions in WordNet
n. becoming proficient in the use of something; having mastery of; "his mastering the art of cooking took a long time" the act of making a master recording from which copies can be made; "he received a bill for mastering the concert and making 100 copies" ...

Wikipedia Word definitions in Wikipedia
Mastering may refer to Audio mastering , the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device, the master Bus mastering , a feature supported by many data bus architectures that enables ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Master \Mas"ter\, v. t. [imp. & p. p. Mastered ; p. pr. vb. n. Mastering .] To become the master of; to subject to one's will, control, or authority; to conquer; to overpower; to subdue. Obstinacy and willful neglects must be mastered, even though ...

Wiktionary Word definitions in Wiktionary
n. Becoming professional in the use of something; having mastery of vb. (present participle of master English)