Register rhymes with:
regester, regester, regester, alister, allister, armbrister, ballester, banister, barrister, burmester, callister, cannister, chedester, chidester, chronister, collister, edmister, flemister, forister, hardister, hiester, hollister, keister, kiester, macallister, regester, reister, riester, sinister
Register sounds like:
racketeer, rakestraw, raster, rastetter, raxter, reactor, rector, rectory, regester, registrar, registry, reister, requester, resetar, rester, restore, restorer, richter, riester, riesterer, righter, rister, roaster, rochester, rocketry, roister, rooster, rossiter, roster, royster, rustier