While copy-editing an article for a journal, I came across the word “upgradation” underlined red by MS Word (It's underlined red even as I type it in Chrome).
The publishers of the journal recommend following the Oxford dictionary. Now, strangely one of Oxford's sites returns 'No results found for “upgradation”' on searching, while another defines it as 'the fact of upgrading something'.
The Cambridge dictionary site also has an entry for the word.
Both, Oxford Learner's Dictionary's site and the Cambridge Dictionary's site are complete with US as well as British pronunciations. As far as I know the word is very much in use at least in Indian English.
I am unable to make sense out of these findings. Please share if you have any idea why there is such a predicament over “upgradation”.