A mixed drink containing Coke and vomit
"This rum and Coke tastes like somebody puked in it"
"Oh sorry, I thought you said 'Roman Coke'"
A Roman Coke is the name for an alcoholic drink containing Rum and soda. The title comes from the pronunciation of the beverage by the drinker after they have consumed a couple.
1: "Hey Colin, what're you drinking?"
2: "Ohhhh, Rom an' coke (read: Roman Coke)."
1: "Aiiight then."