canal (noun)
1: (astronomy) an indistinct surface feature of Mars once thought to be a system of channels; they are now believed to be an optical illusion
2: 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" [syn: duct, epithelial duct, channel]
3: long and narrow strip of water made for boats or for irrigation v : provide (a city) with a canal [syn: canalize, canalise]