'apathetical' originates from Greek, specifically the word 'apathēs', where the prefix 'a-' meant 'without' and 'pathos' meant 'feeling'.

'apathetical' changed from the adjective 'apathetic' (from Late Latin/Greek formations) by adding the adjectival suffix '-al' to form 'apathetical' in modern English.

Initially, the root meant 'without feeling' in Greek, and over time it evolved into the modern English sense of 'showing little or no interest or emotion'.