According to a report this week, supersede is the most commonly misspelt word in English
I have always believed that people tend to spell it with a 'c' because of a kind of word association: it means, in a sense, to win or to prevail. Therefore somebody must have lost, given in, yielded or ceded (even conceded)
Our Latin teacher taught us otherwise. It comes from the Latin for ‘sit upon’ – so think sedentary & remember the 's'
For my generation at least, it also amused the adolescent mind. Does anybody still use the word situpon as a noun, to refer to a part of the anatomy?
Confusingly, however, The Times (possibly quoting Collins Dictionary, who did the research) says that supersede comes from a Latin word meaning desist
My copy of Chambers agrees with my Latin teacher.
As does the OED. Which also adds, helpfully, that in Old French & (often) in Medieval Latin, it was spelt with a c!
All of which just goes to prove – something or the other