Affirm rhymes with:
reaffirm, confirm, ferm, firm, infirm, reaffirm, reconfirm, berm, confirm, ferm, firm, germ, germe, herm, hurm, infirm, long-term, reaffirm, reconfirm, schirm, sperm, squirm, sturm, term, therm, thurm, worm, wurm
Affirm sounds like:
abermin, aborn, abraham, abrahamian, abram, abramo, abron, apron, auburn, avraham, avram, avrim