Percival Lowell misunderstanding the Italian word “canali”[1] should rank pretty high in terms of similar phenomena and is probably the most impactful example.
It looks like Wikipedia [1] has a better explanation of the actual misunderstanding, the page you linked wasn't very clear to me (Italian "canali" corresponds to English "channel", not English "canal").
unwind|6 months ago
[1]: https://en.wikipedia.org/wiki/Martian_canals#Supposed_%22dis...