There is no such a Turkish word as voyn. It must be something different.

Gokuyum, according to this article it´s a word used in local Turkish dialects in, amongst other places, Fethiye. http://www.eksisozluk.com/show.asp?t=voyn&iphone=1&__target=Topic118111121110. That would explain why it is used on the Fethiye Facebook page, where I have also seen it written as woyn and wooyn (no doubt for effect). Whether it is an ´actual´ turkish word should be decided by turks. We have words in my local English dialect (Brummie - from Birmingham) which are not recognised as proper words by all English people.

Thats good beaton that you are curious about the regional accents or sayings, but at the end of the day that word is not counted as "Standart Turkish Word " as it is only used in a small region. what I mean is that if you stop 100 people randomly on the street in Ankara  and ask them if they know what "voyn" means I am 100 percent sure they will say that they never heard that word before or they will just speculate on it.

Thanks Tunci for the explanation but as I normally go to the Fethiye region when I holiday in Turkey I was curious to know what the word meant. When I first raised the question I had no idea it was a regional word only as I mistook it for a web abbreviation. When I next visit Ovaçik near Fethiye I will use voyn and see if I get a reaction. I will remember not to use it when I visit Istanbul next October though