Fiefdoms rhymes with:
adam's, adams, adams', addams, addendums, condoms, freedom's, freedoms, kingdom's, kingdoms, mcadams, memorandums, modems, needham's, odoms, oldham's, referendums, saddam's, sedums, sheikdoms, tandem's, wadhams
Fiefdoms sounds like:
fading, fadness, fathoms, fattening, feeding, feedings, fetting, feuding, fidenas, fifteens, fitness, fitting, fittings, footing, footings, fthenakis, futons