'arithmic' originates from Greek, specifically the word 'arithmētikos', where the root 'arithmos' meant 'number'.

'arithmic' developed in English from Late Latin/Medieval Latin terms such as 'arithmeticus' (and via Old French 'arithmetique'), which in turn came from Greek 'arithmētikos' (derived from 'arithmos').

Initially it meant 'of or pertaining to numbers/arithmetic', and this core meaning has remained largely unchanged in modern usage.