'amyatonic' originates from Greek, specifically the word 'a-' meaning 'without' and 'myatonic' derived from 'myo' meaning 'muscle' and 'tonic' meaning 'tone'.

'amyatonic' was formed by combining the Greek prefix 'a-' with 'myatonic', which itself evolved from the Greek 'myo' and 'tonic'.

Initially, it meant 'without muscle tone', and this meaning has largely remained the same in modern usage.