Believability rhymes with:
survivability, accessibility, advisability, comparability, credibility, culpability, deniability, dependability, desirability, disability, durability, eligibility, enforceability, favorability, flammability, gullibility, inability, inevitability, instability, invincibility, invulnerability, liability, maneuverability, marketability, permeability, portability, predictability, profitability, readability, respectability, stability, suitability, survivability, sustainability, taxability, transferability, unavailability, unbreakability, unpredictability, unprofitability, unreliability, variability, visibility, vulnerability
Believability sounds like:
belfield, bielefeld, bielefeldt, billfold, blauvelt, blueblood, blueblooded, bluefield