understudy

• n. 代理；代役
• vt.代役の練習をする；代役を務める；現場で演技をする
• vi. 代役を務めることを学ぶ

under-、underneath、study、learning、understudiesの略。

understudy (v.)

also under-study, 1852, in the theatrical sense "memorize a part so as to be capable of performing on short notice it in the absence of the one to which it is assigned," from under + study (v.). The noun is attested from 1848, translating Italian supplimento.

1. The leading player is ill.Let his understudy to appear on the scene.

主役俳優が病気になり、代役を出場させた。

2.He was an understudy to Charlie Chaplin on a tour of the USA.

チャーリー?チャップリンの米ツアー期間中の代役。

3.The understudy was substituted when the leading actor fell ill.

主役俳優が病気になり、代役が代役を務める。

4.The understudy is substituted when the leading actor falls ill.

「主役俳優が病気になり、代役が代役を務める」。

5.When the star became sick，his understudy steped into his part.

この映画スターが病気になったとき、候補俳優が彼の役を務めた。