あの芝居者は舞台の上で生き生きとしている。
That actor comes alive on stage.
Common word for actor, often with a nuance of skill or craft. 芝居者 carries a more historical or literary flavor.
Compound of 芝居 (しばい, 'play, drama') and 者 (もの, 'person'). The exact historical derivation is uncertain, but the term has been used since the Edo period to refer to theater people.