Bubble

a nearly spherical body of gas contained in a liquid.
a small globule of gas in a thin liquid envelope.
a globule of air or gas, or a globular vacuum, contained in a solid.
anything that lacks firmness, substance, or permanence; an illusion or delusion.
an inflated speculation, especially if fraudulent:
The real-estate bubble ruined many investors.
the act or sound of bubbling.
a spherical or nearly spherical canopy or shelter; dome:
The bombing plane bristled with machine-gun bubbles. A network of radar bubbles stretches across northern Canada.
a domelike structure, usually of inflated plastic, used to enclose a swimming pool, tennis court, etc.
Informal. a protected, exempt, or unique area, industry, etc.:
The oasis is a bubble of green in the middle of the desert.
an area that can be defended, protected, patrolled, etc., or that comes under one’s jurisdiction:
The carrier fleet’s bubble includes the Hawaiian Islands.
a sudden, small, temporary change or divergence from a trend:
In May there was a bubble in car sales, with three percent more being sold than last year.
to form, produce, or release bubbles; effervesce.
to flow or spout with a gurgling noise; gurgle.
to boil:
The tea bubbled in the pot.
to speak, move, issue forth, or exist in a lively, sparkling manner; exude cheer:
The play bubbled with songs and dances.
to seethe or stir, as with excitement:
His mind bubbles with plans and schemes.
to cause to bubble; make bubbles in.
Archaic. to cheat; deceive; swindle.
bubble over, to become lively:
The last time I saw her she was bubbling over with enthusiasm.
Contemporary Examples

The Confusion of the Jews Bernard Avishai May 28, 2012
If I Did It Paul Kedrosky October 22, 2008
Can Europe Be Saved? Henry Farrell, John Quiggin October 3, 2011
Will Your Favorite Shows Be Canceled? Kim Masters May 11, 2009
How Leo Went From Bratty to Brilliant Gina Piccalo July 14, 2010

Historical Examples

The House of a Thousand Candles Meredith Nicholson
Vivian Grey Earl of Beaconsfield, Benjamin Disraeli
William Lloyd Garrison Archibald H. Grimke
The Shadow of a Crime Hall Caine
The Modern Railroad Edward Hungerford

noun
a thin film of liquid forming a hollow globule around air or a gas: a soap bubble
a small globule of air or a gas in a liquid or a solid, as in carbonated drinks, glass, etc
the sound made by a bubbling liquid
something lacking substance, stability, or seriousness
an unreliable scheme or enterprise
a dome, esp a transparent glass or plastic one
verb
to form or cause to form bubbles
(intransitive) to move or flow with a gurgling sound
(intransitive) ; often foll by over. to overflow (with excitement, anger, etc)
(intransitive) (Scot) to snivel; blubber
n.
v.