Frothy describes something covered with or full of small bubbles, like foam. When you pour root beer into a glass too fast, you get a thick, frothy layer of foam on top. Hot chocolate becomes frothy when you stir it vigorously or add whipped cream. Ocean waves crashing on rocks create frothy white surf.

You can make milk frothy by whisking it rapidly, which is what a barista does when making a cappuccino. A frothy mixture is light, airy, and filled with tiny pockets of air.

Frothy can also describe something that seems light and insubstantial, lacking serious content. A frothy novel might be fun and entertaining but not particularly deep or challenging. A frothy conversation stays on cheerful, surface-level topics rather than tackling anything heavy or important. In this sense, frothy isn't necessarily an insult: sometimes you want a frothy comedy after a long day, just like sometimes you want a rich milkshake instead of plain milk. The word simply indicates something bubbly, light, and easy to enjoy.