bubble - noun

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

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

an impracticable and illusory idea

a dome-shaped covering made of transparent glass or plastic

bubble - verb

• form, produce, or emit bubbles
• flow in an irregular current with a bubbling noise
• rise in bubbles or as if in bubbles
• cause to form bubbles
• expel gas from the stomach

bubble - thesaurus

babble   belch   burble   burp   eruct   guggle   gurgle   ripple