It's basically the opposite of 'yas'. Like every person is gonna use it to express their disguist, dislike.
Like it's gross, pathetic or you just don't like it.
Obviously it's the short form of 'yas' (the word from the gay culture and Gaga's fans that every straight girl says) + NOT.
-OMG HAVE YOU SEEN EMMA'S NEWBOYFRIEND?
-YES GIRL. IT'S soOOooOo YASN'T! EW!
Sexy looking Cuban guy.
He is very into fashion.
He likes and enjoys giving a good impression.
He usually works out, and eats healthy.
Loves to make you smile.
Has an excellent body.
If you have a Yasniel, don't let go of him for he is more than just any guy.
Super smart, just wait and find out.