Decelerated rhymes with:
accelerated, accelerated, accelerated, exhilarated, accelerated, adulterated, ameliorated, aspirated, cogenerated, commemorated, corroborated, degenerated, deliberated, deteriorated, enumerated, eviscerated, exasperated, exhilarated, exonerated, federated, inaugurated, incarcerated, incinerated, invigorated, liberated, moderated, obliterated, proliferated, redecorated, refrigerated, regenerated, reinvigorated, reiterated, reverberated, unadulterated, unenumerated, unincorporated, unsaturated, venerated
Decelerated sounds like:
decelerate, declared, discolored