Meaning

noun (astronomy) an indistinct surface feature of Mars once thought to be a system of channels; they are now believed to be an optical illusion

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

noun long and narrow strip of water made for boats or for irrigation

originBorrowed from Middle French canal, from Old French canal, from Latin canālis (“channel, canal, narrow passage”), from canna (“reed, cane”), from Ancient Greek κάννα (kánna, “reed”), from Akkadian 𒄀 (qanû, “reed”), from Sumerian 𒄀𒈾 (gi.na). Doublet of channel. See also cane and -al.

Etymology from Wiktionary, CC BY-SA 3.0