chi·as·mus 
(kī-ăzməs)
(kī-ăzməs)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.]