The short definition of "flexer". Juanchy is usually a person that has a future brighter than a Rolex. Juanchy is also a way to call a person who has a long penis.
If you meet someone with these caracteristics, you´ll instantly know he is a Juanchy.
Juanchys usually care a lot about their friends or loved ones, they give them anything they need.
Juanchys are also pretty hot... :$