understudying

Verb

understudy (third-person singular simple present understudies, present participle understudying, simple past and past participle understudied)

1. (transitive) To study or know a role to such an extent as to be able to replace the normal performer when required.
2. (transitive) To act as an understudy (to someone).
3. (transitive) To act in a similar manner to some known person.
   • That lean gentleman had apparently understudied Pharaoh of old and hardened his heart.1935, Owen Conquest, Morny's Master Stroke

See all 4 meanings of understudy