Source : Webster's Revised Unabridged Dictionary (1913)

Hubble-bubble \Hub"ble-bub`ble\, n.
   A tobacco pipe, so arranged that the smoke passes through
   water, making a bubbling noise, whence its name. In India,
   the bulb containing the water is often a cocoanut shell.

Source : WordNet®

hubble-bubble
     n : an oriental tobacco pipe with a long flexible tube connected
         to a container where the smoke is cooled by passing
         through water; "a bipolar world with the hookah and
         Turkish coffee versus hamburgers and Coca Cola" [syn: {hookah},
          {narghile}, {nargileh}, {sheesha}, {shisha}, {chicha}, {calean},
          {kalian}, {water pipe}, {hubbly-bubbly}]