Any tube or canal by which a fluid or other substance is conducted or conveyed.
- An often enclosed passage or channel for conveying a substance, especially a liquid or gas.
- Anatomy A tubular bodily canal or passage, especially one for carrying a glandular secretion: a tear duct.
- A tube or pipe for enclosing electrical cables or wires.
- To channel through a duct: duct the moist air away.
- To supply with ducts.