Concrete slump is a measure of the consistency or workability of freshly mixed concrete. It refers to the degree of deformation or "slump" that occurs when a sample of concrete is placed and then allowed to settle or slump under its own weight. Slump is typically measured in inches or millimeters and provides an indication of the water content, workability, and flowability of the concrete mixture. Concrete with a high slump is more workable and easier to place and finish, while low-slump concrete is stiffer and harder to work with. The appropriate slump for a given concrete mixture will depend on various factors such as the project specifications, placement method, and environmental conditions.