To master something means to learn it so thoroughly that you can do it with skill and confidence. When you master multiplication tables, you know them cold and can solve problems quickly. When a pianist masters a difficult piece, her fingers move across the keys with precision and feeling.

Mastering something takes dedicated practice over time. You don't master chess by playing once or twice; you study strategies, play hundreds of games, learn from mistakes, and gradually develop real expertise. A chef who has mastered cooking can adjust recipes by instinct and create delicious meals without needing to measure every ingredient.

The word also means to gain control over something challenging. You might master your nervousness before giving a speech, or master a new skateboarding trick after many attempts.

A master (as a noun) is someone who has achieved this high level of skill. A master carpenter can build beautiful furniture. A master teacher knows their subject deeply and helps students learn effectively. In earlier times, craftspeople learned trades by working as apprentices under masters who taught them everything about the craft.

The word carries a sense of excellence earned through effort: mastery doesn't happen overnight, but when you finally master something difficult, that achievement belongs to you completely.