<p><strong>Verb</strong></p><ul><li>(used with object) to learn (a role) in order to replace the regular actor or actress when necessary.</li><li>to act as understudy to (an actor or actress): to understudy the lead.</li></ul><p><strong>Noun</strong></p><ul><li>(plural understudies) a performer who learns the role of another in order to serve as a replacement if necessary.</li></ul>