Viability rhymes with:
ability, acceptability, adaptability, admissibility, affordability, amiability, applicability, availability, capability, combinability, compatibility, comprehensibility, debility, deductibility, electability, feasibility, flexibility, inaccessibility, invisibility, irresponsibility, irritability, legibility, malleability, overwhelmability, palatability, possibility, probability, rehability, reliability, responsibility, susceptibility
Viability sounds like:
valade, valda, valeda, valet, valid, valida, validate, validated, valided, validity, vallette, vallot, valued, vault, vaulted, veiled, veillette, velayati, velda, velotta, velte, villette, violate, violated, violet, violeta, violett, violetta, violette, vivaldi, vlad, vliet, vold, voleta, volt, volta