Adjective describing something extremely obnoxious and rude.
Comes from the word "snuff", or an obnoxious and rude brat, somebody stuck up.
Molly- "Can you believe Stacy?"
Polly- "What'd she do?"
Molly- "She like, totally spilled her strawberry milkshake cocktail all over my new loafers!!"
Polly- "Wow, that's so snuffish."