A Sybil, named after the famous psychiatric case of Shirley Mason who reportedly had 16 personalities, and popularized by the book and movie "Sybil" is somebody who acts moody and irregularly. In a self-description, it may refer to a feeling of being "not quite oneself".
Just an hour ago, she seemed fine, now she's lost her temper again. She's a real Sybil.
The most gorgeous girl in the world. She is amazing and will melt your heart with just her smile. She is independent and has more swag than most men can handle. She is a rare find and well worth the effort it takes to get inside her heart. Once there she will do anything for you and make you feel like no one ever has.
I met this girl named Sybil and life will never be the same.
In medieval England a Sybil roamed from village to village telling people's fortunes. The name referred to her profession. Unfortunately, this was very witchlike and most Sybil's were burned or drowned to test their disposition.
A Sybil visited the village yesterday and said we would all be burned at the stake in the weeks to come