Fab rhymes with:
prefab, ab, bab, babb, cab, colab, crab, crabb, crabbe, dab, drab, flab, gab, glab, grab, grabbe, jab, knab, knabb, krabbe, lab, labbe, mab, macnab, mcnab, mcnabb, nab, nabb, prab, prefab, rab, rabb, sabb, scab, schab, slab, stab, tab, tabb
Fab sounds like:
f, f., fabia, fabio, fae, fahey, fahy, fao, fava, fave, favia, faw, fay, faye, fe, feb, fee, few, fey, fi, fief, fife, fifi, five, fob, foe, foia, foie, foo, fop, fouhy, foy, foye, fu, fua, fye, fyfe, fyffe