slacken
verb [ I or T ] uk/ˈslæk.ən/ us/ˈslæk.ən/
(LESS TIGHT)
（使）变松，（使）松开
to (cause to) become loose
Slacken the reins or you'll hurt the horse's mouth. 松开缰绳，否则你会弄伤马的嘴。
(LESS ACTIVE)
放慢，放松，减缓
to (cause to) become slower or less active
He stooped to pick it up, without slackening his pace (= without walking more slowly). 他弯腰将它拾起，并没有放慢脚步。
The pace of trading slackened during the winter months. 冬天那几个月里贸易活动明显减少。
The management expects demand to slacken (off) in the New Year. 管理层预计新年期间需求会减少。
The car's speed slackened (off) as it went up a steep hill. 汽车上陡坡时速度减慢了。
Most people slacken off/up at the end of a day's work. 大多数人在一天工作快结束时都会松懈下来。