5AM Vince

When someone stays up all night drinking and carousing, only to transform into an alternate personality after a certain time or quantity of alcohol. After the transformation, this person acts significantly out-of-character and may frighten or confuse those around them. May include significant re-enactment of television or movie characters or spontaneous eruptions into song - both hair metal and show tunes.

Bro, he went to the city and stayed out all night. Dude went 5AM Vince on the crew!

Dayyumm! She went ALL 5AM Vince on his ass!