Here's what rhymes with annihilatingly.
gratingly irritatingly nauseatingly titillatingly hesitatingly fascinatingly penetratingly accommodatingly aggravatingly unhesitatingly deprecatingly devastatingly calculatingly illuminatingly infuriatingly invigoratingly humiliatingly ingratiatingly intimidatingly excruciatingly exasperatingly Words that almost rhyme with annihilatingly
ragingly engagingly amazingly rakishly basically creatively unfailingly scathingly unavailingly abrasively piratically evasively meditatively animatedly pervasively uncomplainingly entertainingly imitatively jadedly authoritatively persuasively appreciatively collaboratively prosaically manipulatively qualitatively administratively algebraically legislatively complicatedly lackadaisically exaggeratedly exasperatedly