Here's what rhymes with extantness.
Words that almost rhyme with extantness
exodus testiness dextrousness estimates excellence gentleness restlessness tetanus recklessness pleasantness endlessness senselessness restfulness fecklessness mechanise sensibleness airlessness fetidness zestfulness heftiness edibleness emphasis edifice eminence carelessness helplessness mellitus membranous pestilence blessedness helpfulness carefulness directionless terribleness levelness tepidness evidence eloquence resonance arrogance elegance genesis perilous decadence precipice sensuous tenuous nebulous requisites unpleasantness venomous garrulous pendulous breathlessness emeritus testaments baronets fretfulness healthfulness preciousness sedulous infectiousness defencelessness defenselessness dreadfulness momentousness decimates eventfulness djellabas marabous jellabas elements sentiments settlements negligence relevance elephants emigrants feminists precedence stenosis credulous licentiousness tremulous querulous clarinets petulance registrants decadents megabits relentlessness impetuousness respectfulness portentousness redolence resentfulness secondments housemistress incestuousness neglectfulness inheritance prevalence regiments precedents sediments forgetfulness tenements asparagus preeminence preparedness temperaments conscientiousness irrelevance overemphasis celebrants pretentiousness contentiousness detriments perfectionists tendentiousness tempestuousness intelligence specialists benevolence beneficence incredulous prerequisites geneticists malevolence interrogates contemptuousness nonvenomous developments impediments pathogenesis embarrassments integuments presentiments unpreparedness experiments hydrocephalus angiogenesis morphogenesis nonresidents disinheritance embryogenesis nonspecialists redevelopments spermatogenesis gluconeogenesis