Fief rhymes with:
hafif, aperitif, bas-relief, beef, belief, brief, chief, debrief, disbelief, graef, graefe, graeff, grefe, greif, greiff, grief, hafif, keef, keefe, keeffe, kief, knief, leaf, leif, lief, massif, matif, mccleaf, motif, naef, neef, o'keefe, o'keeffe, okeefe, okeeffe, reef, reif, reiff, relief, rief, saif, salif, seif, seife, sharif, sheaf, stief, thief, vancleef
Fief sounds like:
f, f., fab, fabia, fabio, fae, fahey, fahy, fao, fava, fave, favia, faw, fay, faye, fe, feb, fee, few, fey, fi, fife, fifi, five, fob, foe, foia, foie, foo, fop, fouhy, foy, foye, fu, fua, fye, fyfe, fyffe