• n. 运动；练习；运用；操练；礼拜；典礼
• vt. 锻炼；练习；使用；使忙碌；使惊恐
• vi. 运动；练习

ex-, 向外。-erc, 保护，限制，隐藏，词源同ark, arcane. 即去除限制，进行练习。

exercise

exercise: [14] The notion underlying exercise is of ‘removal of restraint’. It comes ultimately from Latin exercēre, a compound verb formed from the prefix ex- ‘out of, from’ and arcēre ‘restrain, enclose’ (source of English arcane and related to English ark). It has been speculated that this originally denoted the driving of draught animals out into the fields to plough, but however that may be, it soon developed the general senses ‘set to work, keep at work’ and ‘drill, practise’ which form the semantic basis of English exercise.
=> arcane, ark

exercise (n.)

mid-14c., "condition of being in active operation; practice for the sake of training," from Old French exercice (13c.) "exercise, execution of power; physical or spiritual exercise," from Latin exercitium "training, exercise" (of soldiers, horsemen, etc.); "play;" in Medieval Latin also of arts, from exercitare, frequentative of exercere "keep busy, keep at work, oversee, engage busily; train, exercise; practice, follow; carry into effect; disturb, disquiet," literally "remove restraint," from ex- "off" (see ex-) + arcere "keep away, prevent, enclose," from PIE *ark- "to hold, contain, guard" (see arcane).

Original sense may have been driving farm animals to the field to plow. Meaning "physical activity for fitness, etc." first recorded in English late 14c. Also from late 14c. as "a carrying out of an action; a doing or practicing; a disciplinary task." In reference to written schoolwork from early 17c. The ending was abstracted for formations such as dancercise (1967); jazzercise (1977); and boxercise (1985).

exercise (v.)

late 14c., "to employ, put into active use," from exercise (n.); originally "to make use of;" also in regard to mental and spiritual training; sense of "engage in physical activity" is from 1650s. From late 14c. in sense of "train, drill, discipline, educate (someone); develop (a skill) by practice." Related: Exercised; exercises; exercising.

1. His exercise books were full of well deserved red ticks.

他的练习本上尽是些红钩钩，都是他应得的。

来自柯林斯例句

2. Swimming is probably the best form of exercise you can get.

游泳或许是现有的最佳锻炼方式。

来自柯林斯例句

3. A bit of exercise will help lift his spirits.

进行一点儿体育锻炼能帮助他改善情绪。

来自柯林斯例句

4. Lack of exercise can lead to feelings of depression and exhaustion.

缺乏锻炼会导致抑郁和疲劳。

来自柯林斯例句

5. Other amenities, less commonly available, include a library and exercise room.

还有一些不太常有的设施，包括图书馆和健身房。

来自柯林斯例句