Definition of "Bubble" :

noun: a dome-shaped covering made of transparent glass or plastic

noun: an impracticable and illusory idea

"He didn't want to burst the newcomer's bubble."

noun: a speculative scheme that depends on unstable factors that the planner cannot control

"A real estate bubble."

noun: a hollow globule of gas (e.g., air or carbon dioxide)

verb: expel gas from the stomach

verb: form, produce, or emit bubbles

verb: cause to form bubbles

"Bubble gas through a liquid."

verb: rise in bubbles or as if in bubbles

"Bubble to the surface."

verb: flow in an irregular current with a bubbling noise