'accordantly' originates from Middle English, specifically the word 'acordant,' where 'acord' meant 'agreement' and the suffix '-ly' was added to form the adverb.

'acordant' transformed into the modern English word 'accordant,' and eventually became 'accordantly' with the addition of the adverbial suffix '-ly'.

Initially, it meant 'in agreement or harmony,' and this meaning has largely remained the same in modern usage.