Chiasmus Definition

Chiasmus is a figure of speech in which two clauses are related to each other through a reversal of structures to make a larger point, though the reversal does not have to feature the same words as in antimetabole, which could be considered to be a type of chiasmus.  One example often quoted come from Shakespeare's Othello:

Who dotes, yet doubts; suspects, yet strongly loves. (Act 3, Scene iii)

Dotes/loves doubts/suspects are the parallel elements in the sentence , following an ABBA pattern, which is common is simple chiasmus- dotes (A- positive) doubt (B- negative) suspect (B- negative) loves (A- positive).