'aoristic' originates from Greek, specifically the word 'aoristos', where the prefix 'a-' meant 'not' and 'oristos' meant 'defined' or 'limited'.

'aoristic' developed via grammatical terminology: Greek 'aoristos' passed into Late/Medieval Latin and descriptive grammatical usage, and the English adjective 'aoristic' was formed in modern linguistic scholarship to describe things relating to the aorist.

Initially it meant 'not defined' or 'indefinite' in Greek; over time the term became specialized in grammar to refer to the aorist (a simple or undefined aspect/tense), and modern usage retains both the grammatical sense and the extended sense of 'indefinite'.