1. Incongruity, often humorous or tragic, between the perceived and expected outcome of a series of events and the actual outcome
2. The use of words to express something other than and especially opposite the literal meaning
Example: A military-trained sniper took his own life after firing a single bullet through a window, hitting and killing his estranged wife as she sang onstage at a bar in Cheyenne, Wyoming. The song she was singing at the time: Toby Keith's I Love This Bar.