Here's what rhymes with retardable.
double bubble publ trouble rubble stubble dirigible redouble playable addable damnable friable attachable unplayable acquirable flyable beatable tamable uncharitable unbridgeable filtrable vocable unlikable dividable unloveable conformable imperishable imperturbable translatable nonviable unnameable containable ignitable vincible indissoluble exploitable unarguable compoundable transmutable untranslatable indemonstrable Words that almost rhyme with retardable
puddle tuple couple subtle shuttle muddle rebuttal suppl supple huddle cuddle cudgel rappel fuddle scuttle decouple uncouple befuddle oversubtle thermocouple tunnel puzzle bustle tumble buckle chuckle jumble tional juggle tussle bumble pummel duckbill tamale tousle tubful muscle humble bundle jungle funnel muzzle shovel ductile rumble rustle shuffle stumble ductal hovel hustle knuckle muffle mussel ruffle subtile fumble mumble pustule suckle caecal runnel truffle bungle guzzle nuzzle truckle gunnel unbuckle gumball jugful tumbrel struggle fungal autumnal crumble bestowal grumble scuffle smuggle carbuncle phrasal reshuffle snaffle snuggle trundle lungful rumple snuffle mugful pinocle frontal triumphal colourful crustal nuptial subcortical lustful peduncle trustful crumple nonvocal kerfuffle cupsful conformal suboptimal prenuptial duodecimal granduncle prefrontal antifungal distrustful honeysuckle heptagonal disgruntle mistrustful