Here's what rhymes with downcurving.
                        
                        
                    
                                curving  serving  swerving  unnerving  observing  preserving  deserving  reserving  conserving  unswerving  undeserving  Words that almost rhyme with downcurving
cursing  nursing  surfing  birthing  coercing  immersing  unearthing  conversing  reversing  traversing  dispersing  rehearsing  disbursing  curling  curbing  working  learning  burning  turning  occurring  searching  wording  yearning  hurting  lurking  merging  whirling  churning  herding  hurling  incurring  jerking  purging  surging  chirping  skirting  verging  lurching  perching  purring  scourging  shirking  whirring  yearling  emerging  stirring  asserting  bursting  inserting  recurring  sterling  affirming  exerting  blurring  concurring  swirling  alerting  averting  flirting  hurtling  inferring  inverting  manuring  squirming  thirsting  twirling  darning  smirking  spurring  spurting  concerning  referring  returning  disturbing  confirming  converting  preferring  conferring  converging  discerning  diverting  diverging  researching  reworking  deferring  deterring  reverting  usurping  perturbing  perverting  transferring  overturning  reaffirming  subverting  disconcerting