Fluid Conveyance Medium
A Fluid Conveyance Medium is a pathway for fluid to travel from one place to another, either for the purpose of doing mechanical work such as in hydraulics, or for the purpose of consumption at its destination, such as in domestic water systems.
Because of obvious similarities, and for the sake of continuity of logical classification, we consider electrical wires to be fluid. Electrical conduit is therefore a fluid medium, as far as we're concerned. Of course the difference here is that liquid-tight couplings are designed to keep fluids out, rather than in.