'anciently' originates from Middle English, specifically the word 'auncien', where 'auncien' meant 'old' or 'from former times'. The suffix '-ly' was added to form the adverb.

'auncien' from Old French became 'ancient' in English, and with the addition of '-ly', it became 'anciently'.

Initially, it meant 'in ancient times' or 'long ago', and this meaning has remained consistent in modern usage.