a canal for a current of water | long and narrow strip of water made for boats or for irrigation |
a contest of speed | a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance |
any competition | (astronomy) an indistinct surface feature of Mars once thought to be a system of channels; they are now believed to be an optical illusion |
people who are believed to belong to the same genetic stock | |
(biology) a taxonomic group that is a division of a species; usually arises as a consequence of geographical isolation within a species | |
the flow of air that is driven backwards by an aircraft propeller | |