In rhetoric, chiasmus (/kaɪˈæzməs/ ky-AZ-məs) or, less commonly, chiasm (Latin term from Greek χίασμα, "crossing", from the Greek χιάζω, chiázō, "to shape like the letter Χ"), is a "reversal of grammatical structures in successive phrases or clauses – but no repetition of words".[1]
A similar device, antimetabole, also involves a reversal of grammatical structures in successive phrases or clauses in an A-B-B-A configuration, but unlike chiasmus, presents a repetition of words.[2]