This term is used when talking about someone who is overly promiscuous.
It is a combination of multiple sexual transmitted diseases. Usually referenced towards a person who everybody knows to be sexually active, especially when everyone has been with that person. Found to be offensive, yet hilarious.
This term can be used to describe a sexual transmitted disease or can used in reference towards a disgusting person.
1) Dude! You are going with Tiff tonight? Watch out for them gonnahsyphilaids!
2) Ugh... You mean Gonnahsyhilaids? She's disgusting.