If something is plumbeous, it either contains lead or has lead-like qualities, such as being heavy or dark gray in color.
Plumbeous is an adjective that can be used both literally and figuratively. For instance, large storm clouds with a deep gray hue and a heavy appearance might be described as plumbeous, reflecting their similarity to lead despite not being made of it. To use it literally, you could say, "The plumber replaced the old, plumbeous pipes to modernize the system," to describe pipes that are actually made of or contain lead.