This might also be a difference in continent... you have to remember Oscar Wilde is writing in the United Kingdom of Great Britain and Ireland as well as during the mid-nineteenth century (apologies if this is known to you - I don't mean to patronise) and both the meaning of words as well as their "spelling" change faster most people realise - it is just that in English there are a _lot_ of words and there is a limit to how many words change at any one time and though it's difficult for anyone to track at the time, after the fact, once things have settled down for a particular expression, any-one can see it. With other languages with a smaller vocabulary and less geographical range the effect becomes much more concentrated and a greater swathe of the more used vocabulary shifts, though this is changing over time as mass education and mass media reduce the differences in each languages population that geography tends to impose.
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It is - hence my having studied it! - but please only take this as a massive overgeneralisation of the actual situation since all this varies massively with education levels, curriculum content and prescriptiveness, language morphology, cultural norms as well as cultural lynchpins (e.g. In Britain the monarchy's use of English is highly conservative and pins a swathe of (British (RP)) English to older meanings to a greater degree than countries with a more verbally fluid "aristocracy" (those whom society / culture tends to emulate the speech of - the upper class and celebrities in the UK, the middle class, idols and royalty in Japan).)
Sorry... got carried away, hence the nested brackets! ;)