Is "Englishnization" an acceptable term?

Solution 1:

There is already a word for converting something to English:

Anglicization /Anglicisation (AmE/BrE)

1 : to make English in quality or characteristics
2 : to adapt (a foreign word, name, or phrase) to English usage: as a : to alter to a characteristic English form, sound, or spelling b : to convert (a name) to its English equivalent <anglicize Juan as John>

It is almost only ever used to refer to the conversion of words or names, but it only needs a slight expansion of its meaning to cover the conversion of all business communication in a company.

A slight broadening of an existing word, in a way that is consistent with its history and existing usage, seems much preferable than coining a new, awkward phrase.

However! I'm not a Japanese speaker. What is acceptable depends on who has to accept it, so what word is acceptable for this idea is ultimately up to the people who use it. A Japanese speaker unfamiliar with the "English"/"Angle" transformation would probably find "Anglicization" unintuitive, and the n following the sh in "Englishnization" may well be roll off the tongue better for someone coming from a language in which a syllable-final sh doesn't exist and the only syllable-final consonant is n. As it is Japanese workers and companies who are the target demographic that is being sold on the concept, what a Western English speaker thinks might be irrelevant. Not knowing the agenda of Rakuten intimately, I can't be certain.

So, the short version:

• If you are asking what is most acceptable to a Western ear, either "Anglicization" or "Englishization" is what you want.
• If you are asking what is most acceptable to a Japanese ear, I cannot say for certain – but I would not be surprised if "Englishnization" becomes most accepted.
• If you are asking what is most acceptable to both, then you want to compromise and choose "Englishization", no n.

Solution 2:

If one has to choose one of those two alternatives, Englishization is certainly better, as it is simply the root word, English, attached to the suffix, -ization.

There ARE examples of words in which a consonant is inserted between the rood word and -ization: for example, drama + -ization = dramatization. This is to break up the awkward string of vowels (or, in more linguistic terms, to make sure that every syllable has an onset) that would exist in *dramaization. But there is no similar process that would motivate adding an extraneous n to Englishization.

Therefore, my answer is: if you need to attach -ization to English, the only possibility is Englishization. However, as you noted in your question, that word is also not widely used (a Google search for it turns up extremely few results). The "real word" for that concept is anglicization.

Solution 3:

I think anglification rolls off the tongue rather nicely.