If someone slacks off, Bill comes down hard.如果有人怠工，比尔就会严厉地加以斥责。Don't slack off in your studies.不要荒费你的学业。The train slacked off as it came into the station.火车进站时将速度减慢了。It's natural to slack off towards the end of a hard day's work.一天紧张工作快结束的时候有些放松是自然的。