Garak slurping down a root beer floatie
A root beer float, or root beer floatie as Quark called it, was a type of beverage that was made by combining vanilla ice cream with root beer.
While Alexander Rozhenko served aboard the IKS Rotarran in 2374, his crewmate Ch'Targh mockingly suggested that he might prefer root beer (with a lump of ice cream in it) to Klingon bloodwine. (DS9: "Sons and Daughters")
When Badgey took over a Drookmani ship, Goodgey asked Beckett Mariner and Sam Rutherford if they'd like to take a "root beer float break." Mariner answered affirmatively, but acknowledged that they had to stop Badgey first. (LD: "A Few Badgeys More")
According to an account that was anything but canon, on a malfunctioning holoprogram, Quark tried to get Garak to buy a propaganda holoprogram to help bring the Romulans into the Dominion War. He even told him that he would throw in a key chain and half-price root beer floaties. (VST: "Holograms All the Way Down")