Caulk

1. See Calk.
2. a viscous semisolid material of varying composition used to fill in seams of objects which are exposed to water, such as wooden ships or bath tiles; -- called also calk and caulking. After applying in a semisolid form, the material hardens and dries to form a waterproof seal. It is used in the process of caulking. It is sometimes applied together with a rope-like cord to fill larger seams.