duct

The term evokes a sense of guided, enclosed transit. It is most frequently associated with industrial or anatomical systems where the movement of a substance must be strictly contained and directed to a specific destination to avoid leakage or contamination. In a technical sense, it differs from a pipe in that ducts are often larger, rectangular, or specifically designed for air and cables, whereas pipes are typically cylindrical and used for high-pressure liquids. In biology, it describes the precise pathways, like tear ducts, that transport secretions from a gland to a surface.