'allopsychic' originates from Greek, specifically the word 'allos,' meaning 'other,' and 'psychikos,' meaning 'of the soul or mind.'

'allos' combined with 'psychikos' in Greek, and eventually became the modern English word 'allopsychic.'

Initially, it meant 'pertaining to the mind's interaction with the external world,' and this meaning has largely remained the same in modern usage.