definition of
duct

[1] #1 duct n. [epithelial duct, canal, channel] a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance; "the tear duct was obstructed"; "the alimentary canal"; "poison is released through a channel in the snake's fangs". wn

[2] #2 duct n. a continuous tube formed by a row of elongated cells lacking intervening end walls. wn

[3] #3 duct n. an enclosed conduit for a fluid. wn