Here's what rhymes with oncost.
                        
                        
                    
                                cost  lost  crossed  tossed  dost  glossed  exhaust  frost  embossed  holocaust  permafrost  Words that almost rhyme with oncost
coughed  caused  soft  washed  loft  scoffed  wasp  quashed  unwashed  paused  aloft  squashed  massaged  swathed  betrothed  camouflaged  court  got  caught  cart  cocked  cot  gaunt  coursed  not  part  thought  want  heart  short  forced  hot  lot  sort  sought  taught  bought  fault  fought  port  salt  shot  talked  walked  watched  chart  fort  locked  pot  halt  knocked  shocked  wrought  chopped  dot  font  knot  rot  vault  clot  cropped  dart  haunt  malt  mocked  naught  popped  quart  rocked  taut  topped  tort  tot  unlocked  yacht  boxed  hopped  jot  mart  notched  tart  watt  balked  chalked  docked  fart  hart  sot  taunt  wart  brought  marked  start  apart  dropped  plot  spot  stopped  adopt  assault  import  launched  marched  sport  blocked  enforced  forgot  smart  endorsed  escort  impart  parked  slot  blot  consort  flocked  fraught  propped  stocked  thwart  trot  abort  barked  exalt  exhort  forked  parched  scorched  squat  stalked  unmarked  warped  allot  athwart  begot  ensconced  flopped  indorsed  snort  report  support  default  resort  depart  prompt  divorced  embarked  basalt  detente  dwarfed  infarct  rampart  sparked  swamped  bethought  extort  savant  starched  stomped  transport  reinforced  remarked  commandant  distort  confidant  kilowatt  apricot  gestalt  overwrought  restart  counterpart  restaurant  afterthought  distraught  thunderbolt  astronaut  dilettante  disembarked