When a girl is naturally ugly/unattractive, but acquires all the "playing cards" of being attractive in today's world, therefore passing for "hot." Playing cards include, but are not limited to: tight/hugging designer jeans, trendy hairstyle, trendy clothes, hair highlights, etc. Many many girls you see out and about are very ugly-hot.
When you can't decide if a girl is fine or ugly. Sometimes depends on the day. But basically said to a girl who can look good and ugly at the same time.
Mostly applies to emo and hipster kids. Someone is ugly-hot if:
1. You'd hit it.
2. You'd be embarassed if your friends found out.
3. You'd still hit it if they did.
"Look how hot that guy is over there!"
"Are you kidding? Look at that mullet!"
"OK, fine, he's ugly-hot."
When someone is rather unattractive before a weight loss, face altercation ( example, nose job, jaw realigning,etc...) was not full of themselves before the transformation, but after becoming so called "hot" or attractive and becomes a major bitch and having major changes in personality, etc.. super judgemental to other.
"Heidi totally got a case of "Ugly-Hot Girl Syndrome" when she got her face done. She is a total bitch now and completely full of herself."