The expression "pick up the slack" means to take over the work or responsibilities that someone else is not doing or is falling behind on. It refers to making up for a lack of effort or filling in gaps to keep things moving smoothly.

For example, if a team member is not completing their tasks, others might have to pick up the slack by doing extra work to cover for them. It’s about compensating for shortcomings or delays so that the overall goal is still achieved.