A bounded way something is carried through. A conduit holds nothing of its own.
Old French conduit (a leading, escort), from Latin conductus, past participle of conducere (to lead together), from com- (together) + ducere (to lead); a bounded way built to carry something through, holding none of it for itself.
A bounded way something is carried through, which holds nothing of its own by design. Its whole virtue is transparency to what passes.