Webster's Revised Unabridged Dictionary -- Volume AB

Beads of sweat have stood upon thy brow,
Like bubbles in a late disturbed stream.
Shak.

2. A small quantity of air or gas within a liquid body; as, bubbles rising in champagne or aërated waters.

3. A globule of air, or globular vacuum, in a transparent solid; as, bubbles in window glass, or in a lens.

4. A small, hollow, floating bead or globe, formerly used for testing the strength of spirits.

5. The globule of air in the spirit tube of a level.

6. Anything that wants firmness or solidity; that which is more specious than real; a false show; a cheat or fraud; a delusive scheme; an empty project; a dishonest speculation; as, the South Sea bubble.

Then a soldier . . .
Seeking the bubble reputation
Even in the cannon's mouth.
Shak.

7. A person deceived by an empty project; a gull. [Obs.] "Ganny's a cheat, and I'm a bubble." Prior.

Bub"ble, v. i. [imp. & p. p. Bubbled (?); p. pr. & vb. n. Bubbling (?).] [Cf. D. bobbelen, Dan. boble. See Bubble, n.]

1. To rise in bubbles, as liquids when boiling or agitated; to contain bubbles.

The milk that bubbled in the pail.
Tennyson.

2. To run with a gurgling noise, as if forming bubbles; as, a bubbling stream. Pope.

3. To sing with a gurgling or warbling sound.

At mine ear
Bubbled the nightingale and heeded not.
Tennyson.