frothy

Foamy or churned to the point of becoming infused with bubbles.

I like my milkshakes frothy, not flat like this!

When this brown head was obtained the juice was drawn off into barrels, the lees were left in the keeve, and new juice was pumped upon these lees, this, however, produced a white frothy head, similar to that in the remaining keeves.

lightweight; lacking depth or substance

songs with frothy lyrics

a frothy argument

Highly speculative; having high risk and high return.

But we have found it profitable to engage in some trading on our own account, generally in the rather frothy areas.

First, many of the welfare gains of the previous two decades or more turned out to have been illusory, as house and share prices tumbled, jobs disappeared and frothy investment opportunities collapsed.

A serving of beer.