'aruspex' originates from Latin, specifically the word 'haruspex' (also spelled 'aruspex'), where 'haru-/aru-' referred to 'entrails' and 'spex' comes from Latin 'specere' meaning 'to look'.

'aruspex' changed from the classical Latin word 'haruspex' used in Roman religion and was borrowed into English in scholarly and antiquarian contexts (via Renaissance and early modern Latin), preserving the original sense.

Initially, it meant 'one who inspects entrails for omens'; over time it became an archaic or scholarly term in English meaning 'diviner' or was used metaphorically for a soothsayer.