Synonyms for Bubble (same or very similar meaning)
WordNet sense 1 (a speculative scheme that depends on unstable factors that the planner cannot control):
house of cardsWordNet sense 2 (flow in an irregular current with a bubbling noise):
babble, burble, gurgle, ripple, guggleWordNet sense 3 (expel gas from the stomach):
belch, burp, eructFrom the ODE community, based on WordNetadd/edit