Lastingly rhymes with:
interestingly, devastatingly, disappointingly, excruciatingly, fittingly, fleetingly, frustratingly, haltingly, hauntingly, interestingly, mattingly, pointingly, regulatingly, sportingly, unhesitatingly, unwittingly, wittingly
interestingly, devastatingly, disappointingly, excruciatingly, fittingly, fleetingly, frustratingly, haltingly, hauntingly, interestingly, mattingly, pointingly, regulatingly, sportingly, unhesitatingly, unwittingly, wittingly