1. The train slacked up as it came into the station.
2. Slack up the tent ropes before it rains.
3. Please slack up your speed. I can't run as fast as you!
4. The doctor advised Facer to slack up for few days, as his lifestyle was having a bad effect on his heart.
5. It's time to slack up a bit.
6. Slack up before you reach the cross - roads.
7. Don't slack up your effort , as we are getting to the end.