chi·as·mus (kī-āz'məs) n.
pl.chi·as·mi (-mī') A rhetorical inversion of the second of two parallel structures, as in "Each throat/Was parched, and glazed each eye"(Samuel Taylor Coleridge).
[New Latin chīasmus, from Greek khīasmos, syntactic inversion, from khīazein, to invert or mark with an X; see chiasma.]