Thinking of the two forms of the plural of cannon –cannon and cannons– I used ngrams to see what was more popular. Pretty decisively “cannon” is the winner, but the margin narrows as the word itself becomes disused:
100 cannon, 100 cannons
several cannon,several cannons
battery of cannon,battery of cannons
Other words with plural forms that are the same as their singular — related to which, I’m reminded of Marianne Moore’s somewhat striking use of the plural of “deer” in this line of The Octopus (at least, to me this plural s-less “deer” rings out):
What spot could hold merits of greater importance
for bears, elks, deer, wolves, goats and ducks?
Word cannon apparently arises from Greek κάννα — reed.
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