'aphorismical' originates from Greek, specifically the noun 'aphorismos' (ἀφορισμός), where the prefix 'apo-' (ἀπό) meant 'away/from' and the root 'horizein' (ὁρίζειν) meant 'to limit/define'; the English adjective is formed by adding the suffix '-ical' to 'aphorism'.

'aphorismical' developed from the Late Latin/Medieval Latin borrowing 'aphorismus' (from Greek 'aphorismos'), which entered English as 'aphorism' in the 17th century; the adjectival form was later formed by adding the suffix '-ical' to create 'aphorismical' (analogous to 'aphoristic'/'aphoristical').

Initially associated with 'a definition' or a concise statement (the original sense of 'aphorism'), it evolved into an adjective meaning 'pertaining to or resembling aphorisms' — i.e., terse, pithy, or sententious.