'arrhizous' originates from Greek, specifically the word 'arrhizos', where 'a-' meant 'without' and 'rhiza' meant 'root'.

'arrhizous' changed from New Latin/Modern Latin word 'arrhizōs' and eventually became the modern English word 'arrhizous'.

Initially, it meant 'without root', but over time it has retained essentially the same technical sense of 'lacking roots; rootless' in botanical usage.