Fianna rhymes with:
adriana, andriana, ariana, arianna, briana, brianna, christiana, christianna, cusiana, georgiana, gloriana, ileana, indiana, italiana, juliana, lapiana, liliana, lilliana, louisiana, mariana, nelliana, oceana, oriana, piana, pollyanna, triana, viana, viviana
Fianna sounds like:
fabian, fabiani, fabiano, fabien, fahmy, fain, fama, fame, famine, fan, fane, fann, fannie, fannin, fannon, fanny, faubion, fauna, fawn, fayanne, fayme, fayne, feehan, feeney, feeny, fehn, fein, feinman, fema, femia, femina, feminine, femme, fen, fenian, fenn, fennema, fenney, fenno, fenway, feyen, feynman, fiene, fima, fin, fina, finan, fine, fineman, fini, finian, finn, finnan, finne, finney, finnie, fino, fiona, fm, foam, foamy, fomon, fone, foppiano, fume, fumi, fumio, fun, funny