Nabb rhymes with:
knab, knabb, macnab, mcnab, mcnabb, nab, ab, bab, babb, cab, colab, crab, crabb, crabbe, dab, drab, fab, flab, gab, glab, grab, grabbe, jab, knab, knabb, krabbe, lab, labbe, mab, macnab, mcnab, mcnabb, nab, prab, prefab, rab, rabb, sabb, scab, schab, slab, stab, tab, tabb
Nabb sounds like:
naab, nab, nabi, nabob, naef, naeve, naff, naify, naive, nambi, namibia, namphy, nanobaby, nap, napa, napea, napp, nappa, nappi, nappo, nav, nava, nave, navy, neave, neeb, neef, neff, nepa, nephew, neuhoff, neva, neve, neveau, neveu, newbie, newby, newwave, nib, nibbe, niehoff, nimby, nineveh, nip, nipp, nippy, nobbe, nobuo, nope, nouveau, nov, nova, novey, novi, novia, novo, novoa, novy, nub, nuevo, numb, nuova, nuovo, nymph