A masterclass is an advanced lesson or demonstration given by an expert in their field. When a professional violinist visits a music school to teach a masterclass, she doesn't just explain the basics: she shares the deep understanding and refined techniques that come from years of dedicated practice and performance. Students watch her demonstrate subtle details they might never discover on their own, like how to hold the bow for a particular sound or how to interpret a challenging passage.

The word combines master, meaning someone who has achieved exceptional skill, with class, the teaching session itself. Masterclasses appear in many fields: a champion chess player might give a masterclass on opening strategies, or a renowned chef might demonstrate advanced cooking techniques to culinary students.

What makes something a masterclass rather than a regular lesson is the teacher's extraordinary level of skill and the advanced nature of what they share. You wouldn't expect a masterclass in basic addition, but you might attend one on solving complex mathematical proofs. The term has become so popular that people now use it more loosely, sometimes calling any impressive demonstration or performance a masterclass: “That was a masterclass in delivering a presentation.”