A girl (or guy) who styles and models herself after lead singer Hayley Williams
of the band Paramore
To be a Fayley generally requires red hair (in one of Hayley's many styles and colors), yellow skinny jeans, to be incredibly thin, wear lots of New Found Glory shirts and septum piercings. This is a huge stereotype so even having one of these will result in you being named a Fayley.
Fayley's are generally hated for their looks, but overall, aren't always bad people.
A website known for aiding Fayleys is HayleyFashion.
This website will search and find any place you can get specific items worn by Hayley Williams. It is a very informative website, and is easily one of the better sources for all things Hayley (style-wise).
"OMG She's wearing yellow skinnies. What a FAYLEY!"
"Red hair? So a Fayley."