I was reading The Librarian by Salley Vickers when I came across the above word. New-to-me-words tend to jump off the page at me, waving their letters and demanding I look them up in dictionaries, thesauruses and/or websites.
Although I could guess the meaning, I followed the demand and found out, as expected, that the literal meaning is ‘to put on an island’ and the metaphorical is ‘to isolate’. I think it’s definitely more attractive than common or garden ‘isolated’.
Pronunciation was much more interesting; all possibles could be found somewhere on the web. I guess that either:
there are really many ways of saying the word
different dialects pronounce it differently (very differently)
the word occurs in other languages
a lot of people pronounce it wrong.
The one I prefer is to say ‘isle’ in the usual way and add the ‘en’ to it, keeping the stress on the long i.
You’ll have to read the book to see the context the author uses it. I can recommend it as an easy, pleasant read with an unusual ending.