An adjective used to describe something that is simultaneously fantastic and evil or terrible, such as drinking a beer someone was saving for themselves, driving someone else's nice car without permission, or sleeping with someone who's cheating on their boyfriend/girlfriend. In other words, a good thing made better by it being forbidden, but which also causes a bit of guilt.
I promised myself I'd stick to my diet, but I ended up eating some of that cheesecake anyway, and it was sinfulicious.
Man, that married chick is so hot, it's sinfulicious to be watching her like this.
I stole these sunglasses from my brother. They're awesome, but he's pissed. Totally sinfulicious.
something that you smell that makes you want to eat it, ie: fresh baked bread, hot apple pie.
anything that upon smelling awakens a hunger.
also, a good smelling girl.
"I was at the club last night and this snifferlicious girl came and ordered a sex on the beach"
" I was just walking past KFC, and even though I hate that shit, it's still snifferlicious".