bubble (Noun) — A hollow globule of gas (e.g., air or carbon dioxide).
bubble (Noun) — A speculative scheme that depends on unstable factors that the planner cannot control. ex. "a real estate bubble"
bubble (Noun) — An impracticable and illusory idea. ex. "he didn't want to burst the newcomer's bubble"
bubble (Noun) — A dome-shaped covering made of transparent glass or plastic.
bubble (Verb) — Form, produce, or emit bubbles. ex. "The soup was bubbling"
bubble (Verb) — Flow in an irregular current with a bubbling noise. ex. "bubbling brooks"
bubble (Verb) — Rise in bubbles or as if in bubbles. ex. "bubble to the surface"
bubble (Verb) — Cause to form bubbles. ex. "bubble gas through a liquid"
bubble (Verb) — Expel gas from the stomach. ex. "In China it is polite to bubble at the table"