For what it's worth, as an American—living in the South, even—with English as my first language, I have literally never heard the word "radiuses" used (outside,

For what it's worth, as an American—living in the South, even—with English as my first language, I have literally never heard the word "radiuses" used (outside, perhaps, some musings about the plural of the word "radius"). Although my initial reaction was also "look, someone's making another lame Latin plural joke," I quickly saw that it wasn't as inapplicable most other occurrences.