Meaning : (astronomy) an indistinct surface feature of Mars once thought to be a system of channels. They are now believed to be an optical illusion.
Meaning : A bodily passage or tube lined with epithelial cells and conveying a secretion or other substance.
Example :
The tear duct was obstructed.
The alimentary canal.
Poison is released through a channel in the snake's fangs.
Synonyms : channel, duct, epithelial duct
Meaning : Long and narrow strip of water made for boats or for irrigation.