Some idiot who thinks (s)he's amazing...when they're drunk.
"There goes Mr. Shitfaced Wonder again, trying to impress that model at the end of the bar."
A person who you think has a face like shit or a general
Person one: I hate you.
Person 2: Well I hate you to, you shitfaced wonder!
Bob: That woman over there is a shitfaced wonder!
Nathan: Let's hope she doesn't try to kiss us.