To study, as another actor's part, in order to be his substitute in an emergency; to study another actor's part.
- To study or know (a role) so as to be able to replace the regular performer when required.
- To act as an understudy to.
- To be engaged in studying a role so as to be able to replace the regular performer when required.
- A performer who understudies.
- A person trained to do the work of another.