'chiastic' originates from Greek, specifically the word 'chiastikos', where the element 'chi' refers to the Greek letter 'chi' (χ) and 'chiastós' meant 'in the form of an X' or 'crossed'.

'chiastic' developed from the noun 'chiasmus' (from Greek 'chiasmos'/'chiasma' meaning 'crossing'), which passed into Latin and then into English; the adjective 'chiastic' was formed in English to describe things exhibiting a chiasmic form.

Initially it meant 'in the form of an X' or 'crossed'; over time it came to be used specifically for rhetorical or structural arrangements that mirror an A–B–B–A pattern (chiasmus).