n.

1. 请求，恳求[C][（+for）][+to-v]
   The prisoner made a plea for mercy.

   囚犯恳求宽恕。

2. 借口，托辞[the S][（+of）][+that]
   She left the party on the plea of a headache.

   她借口头疼离开了晚会。

3. 【律】抗辩，答辩[C][S1][（+of）]
   He entered a plea of "not guilty" to the charges filed against him.

   针对对他的指控他提出“无罪”的抗辩。

n.

1. a request made in an urgent and emotional manner.
2. Law  a formal statement by or on behalf of a defendant or prisoner, stating guilt or innocence in response to a charge, offering an allegation of fact, or claiming that a point of law should apply.
   ▸an excuse or claim of mitigating circumstances.