Slang term meaning a hardcore guido, usually referred towards characters on the TV show Jersey Shore. Shyciis tend to speak in an uninteligable form of english that rarely anyone but shyciis themselves understand. The context of the speak are generally about tanning, hair gel, fly hair cuts, and bitches.
Shycii 1: Yo what's good wit a fwuckin shycii?
Shycii 2: Yo I got this new hair cut and some new hair gel and I just fwucked this big booty bitch right on the shore brozki.
Shycii 3: Yo brosef you ride the jetskiis?
Shycii 1: Nah brah I'm a fwuckin saaaa.