1. (输送液体或气体的)管道,管子
A duct is a pipe, tube, or channel which carries a liquid or gas.

2. (人体内输送泪水、胆汁等的)导管
A duct is a tube in your body which carries a liquid such as tears or bile.

1. an enclosed conduit for a fluid

2. a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance

e.g. the tear duct was obstructed
the alimentary canal
poison is released through a channel in the snake's fangs

Synonym: epithelial ductcanalchannel

3. a continuous tube formed by a row of elongated cells lacking intervening end walls