In continue to the definition by
Spiel Brickner, which was rather accurate, I'd like to add a couple of things.
While using the word "
blyat" as a link word (regardless to its meaning) , there are
no rules for where to place this word in
the sentence. You may place it anywhere in the sentence as many times as possible, even after each word if you will, and it will still remain correct russian grammar.
The bets anology demonstrating it, is the hebrew word "keilu", which northern Israeli bitches use similary as a link word placing it randomly in the sentence regardless the meaning of the word itself.
(A little
exaggerated example, even though you can find
russian people talking this way)
Yesterday
blyat I went to this party, blyat, and it was so lame blyat that even after I got drunk blyat I didn't feel like dancing blyat.