bubble

(bŭbˈəl)

1. A thin, usually spherical or hemispherical film of liquid filled with air or gas: a soap bubble.
2. A globular body of air or gas formed within a liquid: air bubbles rising to the surface.
3. A pocket formed in a solid by air or gas that is trapped, as during cooling or hardening.
4. a. The act or process of forming bubbles.
   b. A sound made by or as if by the forming and bursting of bubbles.
5. Something insubstantial, groundless, or ephemeral, especially:
   a. A fantastic or impracticable idea or belief; an illusion: didn't want to burst the new volunteers' bubble.
   b. A speculative scheme that comes to nothing: lost money in the real estate bubble.
6. Something light or effervescent: “Macon—though terribly distressed—had to fight down a bubble of laughter” (Anne Tyler).
7. A usually transparent glass or plastic dome.
8. A protective, often isolating envelope or cover: “The Secret Service will talk of tightening protection, but no President wants to live in a bubble” (Anthony Lewis).

1. To form or give off bubbles.
2. To move or flow with a gurgling sound: a brook bubbling along its course.
3. To rise to or as if to the surface; emerge: “Since then, the revolution has bubbled up again in many forms” (Jonathan Schell).
4. To display irrepressible activity or emotion: bubbling over with excitement.