Here's what rhymes with diachronically.
chronically conically phonically laconically bionically sardonically harmonically demonically mnemonically electronically ultrasonically monotonically histrionically hydroponically Words that almost rhyme with diachronically
comically analogically melodically periodically methodically diabolically knowledgeably lethargically alcoholically bucolically historically philosophically symbolically technologically pedagogically episodically genealogically ethnologically demagogically vitriolically metabolically catastrophically exorbitantly prehistorically anthropomorphically