(1)行为(动)(activity，process，or fact of doing sth;using energy，force，power for some purpose)[U]：take～immediately to prevent trouble马上采取行动以防麻烦发生;call sb into～使某人开始行动;go (come) into～开始行动;All～is based on judgements.一切行为基于判断。The time has come for～.是采取行动的时候了。an emergency requiring immediate～要求立即采取行动的紧急情况;make quick～sketches 画快速动作素描;a man of～进取的人;〖同〗operation，activity;〖反〗inaction，inactivity;

(2)行动，举动(something done;act;deed)[C]：A～s speak louder than words.行动胜过言语。A～s are more important than words.行动比言语更重要。Judge a person by his～s，not by what he says.判断一个人要观其行，而不是听其言。regret one's bad～s 后悔自己做的错事;You've done a good～.你做了一件好事。take responsibility for one's～s对自己的行为负责;Their～s were rather hasty.他们的行动太仓促。〖同〗 act，deed;

(3)(马、运动员的)动作姿态(way or manner of moving)[C，通常sing]：a fast bowler with a fine～动作优美的快速投球手;The horse had a fine～when it jumped the fence.那匹马跳过围栏时的姿态很优美。

(4)(身体、机器部件的)机(功)能(way of functioning)[C，通常sing]：The～of the heart is like a pump.心脏的功能有如水泵。the～of the liver in digestion 肝脏在消化过程中的功能;Tennis needs a good wrist～.打网球需要腕部机能好。the～of a machine 机器的功能;The～of this crank turns the wheel.这曲柄的功能是使轮子转动。An electric fault put my computer out of～.断电使我的电子计算机不能运行了。My car's out of～today.我的车子今天出毛病了。You can set the machine into～by pressing the button.按这个钮你可以启动这台机器。〖同〗power，force，work;

(5)机械装置(operating parts of a machine or instrument)[C，通常sing]：The～of this piano/that gun/the clock is becoming stiff.这钢琴/那枪/钟的机件不灵活了。

(6)影响，作用(effect or influence)[C，通常sing][N(on)]：the～of water on rock水对岩石的作用;the～of wind on a sail风对风帆的作用;the～of light on film/ice/nerves 光对胶片/冰/神经的作用;the corrosive～of acid on metal 酸对金属的腐蚀作用;Chlorophyll is produced in plants by the～of light.叶绿素是光作用于植物生成的。

(7)军事行动，战斗(fight(ing) in a war between armies or navies)[U;C]：be killed in～阵亡;reports of military～战斗报导;He has seen～in two wars. 他经历过两次战争的战火洗礼。I witnessed a naval～.我曾亲眼目睹了一次海战。The～lasted two hours.那次战斗持续了两个小时。Our troops fought an～against the enemy. 我们的部队对敌人采取了军事行动。send the troops into～ 把部队投入战斗;〖同〗fighting，battle;

(8)法律程序，诉讼(legal case;lawsuit)[U;C]：take～against sb in the courts 在法院向某人起诉;take legal～提出法律诉讼;bring an～for divorce against one's wife 提出和妻子离婚的诉讼;〖同〗suit;

(9)情节(activities or events of a story，film or play)[U]：The～of the film took place/is set on an island.该电影的故事情节发生在一个岛上/以一个岛为背景。the～of a scene 一幕戏的情节;It was a boring movie with no～.这是一部没有情节的乏味电影。〖同〗movement，excitement;〖反〗dialogue;

in action 1)在运转：Is the motor still in～? 发动机还在运转吗? 2)从事活动：Our basketball team is in～tomorrow.我们的篮球队明天有比赛。

← act v;

→′actionable adj 可提起诉讼的;in′action n 不活动(活跃);re′action n;

【辨异】 action 与act、deed 和exploit的区别见ACT。