This is Bulgarian, and its name would be written in that language as мартеница. I have been to Bulgaria, but I think I was given mine at a party in Oxford. What I was told is that it symbolises spring. You start wearing it on the first of March, and continue until you see the first stork (or possibly the first tree in leaf: I can't remember). You then throw it into a wood or under a tree. I may also have been told that the colours relate to a legend about two babies abandoned in a snowy wood and saved by a stork which tears out its feathers to cover them with. The white stands for the snow or the feathers, and the red for the stork's blood.
My reading found numerous other origin-legends, some linking the martenitsa to the founding of Bulgaria. But everyone seems to agree that this adornment is worn to give thanks for the ending of the long and brutal winter. With which I can fully agree. I shan't be throwing mine away, though, because I wouldn't be able to get another to replace it.
The jacket holding the martenitsa came from the vintage shop Unicorn in Ship Street, Oxford. I buy a lot of my clothes there, as posts to come will show, and recommend it.