'world-soul' originates as an English calque of Latin 'anima mundi,' where 'anima' meant 'soul' or 'breath' and 'mundus' meant 'world'.

'anima mundi' was used in ancient Greek and Roman philosophy (e.g. Plato, the Stoics); through Medieval Latin and Renaissance writings the idea was translated or rendered in English as 'world-soul' in early modern texts and later philosophical literature.

Initially it referred to the animating principle or soul of the cosmos in classical thought; over time the phrase has retained that core sense but come to be used more narrowly in philosophical, religious, or poetic contexts in modern English.