Betwixt rhymes with:
affixed, blixt, fixed, intermixed, mixed, mixte, nixed, sixed, transfixed, unmixed
Betwixt sounds like:
badgett, baptist, baptista, baptiste, baptized, bathgate, batista, batiste, battista, battiste, battisti, bautista, bedecked, bedgood, bedside, bethesda, bewitched, bidgood, bodeguita, botched, bud-test, buddhist, budged, budget, budgeted