Final answer:
The definition of slump in the context of concrete is a test that measures the rigidity (consistency) of uncured concrete, indicating its workability.
Step-by-step explanation:
The term slump refers to a test used to determine the rigidity (consistency) of uncured concrete. Specifically, this slump test measures concrete's workability shortly after mixing but before it has set. The process involves filling a conical mold with the concrete mixture, lifting the mold, and then measuring the distance the concrete subsides, or 'slumps.'
The more it slumps, the wetter and more fluid the concrete is, suggesting a lower viscosity and higher workability, which can be important for ensuring the concrete can be easily shaped and worked with before it hardens.