A person or thing beyond the stated number, or beyond what is necessary or usual.

额外；多余多余的人或物。

Esp. a person employed not for regular service, but merely to fill the place of another or to meet a need.

临时雇员。

Actor which a small non-speaking part, as one of a crowd or of a company of soldiers, etc.

龙套；临时演员。

Exceeding the number stated or required.

定数以外的；额外的。

Substitute.

替代的。