2. An alcoholic beverage
3. A form of fellatio with a mouthful of ice.
4. A form of milkshake, commonly found at Wendy's restaurants.
5. To add highlights of bleached color to one's hair. If you are in a boyband, this is a mandatory hairstyle.
2. Let's go have frosty and build a snowman.
3. "Damn. That was the best frosty I've ever had, Wendy."
4. See above
5. "You have nice, frosty hair Lance. Too bad your music totally sucks."
Also used as a term among potheads as something cool or great.
Pothead 2: "Daaaamn that shits frosty! Roll it up!"