(Gr. vnraXXayii, interchange or exchange), a rhetorical figure, in which the proper relation between two words according to the rules of syntax are inverted. The stock instance is that in Virgil, Aen. iii. 61, where dare classibus austros, to give winds to the fleet, is put for dare classes austros, to give the fleet to the winds. The term is also loosely applied to figures of speech properly known as "metonymy" and, generally, to any striking turn of expression.