n. 间谍,情报人员;告发人,告密者
拆分: in-使... + -form-形 + -er名词词尾,动作发出者 ⇒ 使成形者 ⇒ 使一个思想或描述成形者,告诉人某事者。
例:He later became a police informer. 他后来成了警方的线人。 The service had planted its agents and informers in some key positions in industry. 特工处已将特工和密探安插在工业部门的某些重要工作岗位上。
