懒惰是人类的天性，因此才总有人会在工作时“划水”。“划水”，本意是指“用胳膊划的动作（make strokes with one’s arms）”，延伸为“偷懒、怠工（work less hard than you usually do or should do）”，可以用“slack”表示。
这个词起初用于形容偷懒的船夫，当其他船夫在认真划船时，他们会浑水摸鱼把桨从一边拨到另一边（boatmen who would half-heartedly splash their oars from side to side while their colleagues did the actual rowing），后来延伸到工作和学习领域。
- 那个女团成员舞蹈动作都忘了，明显是在划水。
That band member forgot all her dance moves. She is definitely slacking. - 如果有人上班划水，比尔就会严厉地加以斥责。
If someone slacks off, Bill comes down hard.
