take the slack up

take the slack up

 
1. Lit. to tighten a rope that is holding something loosely. Take the slack up if you can. This clothesline is too loose. Do something to take up the slack.
2. Fig. to do what needs to be done; to do what has been left undone. Do I have to take the slack up? Jill did her job poorly and I have to take up the slack.
See also: slack, take, up