'adynamy' originates from Greek, specifically the word 'adynamia,' where 'a-' meant 'without' and 'dynamis' meant 'power or strength.'

'adynamia' transformed into the French word 'adynamie,' and eventually became the modern English word 'adynamy' through medical Latin.

Initially, it meant 'lack of power or strength,' and this meaning has largely remained the same in modern usage.