bubble in Greek

A spherically contained volume of air or other gas, especially one made from soapy liquid.

(by extension) Anything resembling a hollow sphere.

(by extension) Anything resembling a hollow sphere.

(economics) A period of intense speculation in a market, causing prices to rise quickly to irrational levels as the metaphorical bubble expands, and then fall even more quickly as the bubble bursts.

(intransitive) To produce bubbles, to rise up in bubbles (such as in foods cooking or liquids boiling).