The word “mastering” implies having complete control over or a deep understanding of something.
A synonym for “mastering” could be “commanding”. “Commanding” suggests having authority and control. For example, “He has a commanding knowledge of mathematics.” This shows that he has a high level of expertise and control over the subject.
Another synonym is “dominating”. “Dominating” emphasizes being in a position of power or superiority. For instance, “She is dominating in the field of literature.” Here, it means that she has a strong presence and influence in the literary world.
“excelling at” is also a good synonym. It implies being exceptionally good at something. For example, “He is excelling at playing the piano.” This indicates that he is performing at a very high level in piano playing.
All of these synonyms for “mastering” help to describe the state of having a high degree of skill, knowledge, or control over a particular area.