Aposiopesis is a figure of speech, in particular a form of ellipsis, in which the speaker breaks off suddenly in the middle of speaking, giving the impression that he is unwilling or unable to continue. It often portrays being overcome with emotion.
The traditional example of aposiopesis comes from Virgil's Aeneid 1.135:
Another common example comes from William Shakespeare's Julius Caesar, 3.2.104-107, in which Antony interrupts his own speech at Caesar's funeral:
Examples
meaning, in context, "Such rebels I --". This closely mirrors a more contemporary example of aposiopesis, namely, "Why I oughta...".