I have always been fascinated by the difference between sarcasm and irony. According to some of the definitions the meanings are often blurred and many people use one word when they mean the other.
As a public service, I thought I would muddy the waters a little further.
Irony has been defined as "incongruity between what might be expected and what actually occurs."
Sarcasm is "a mode of satirical wit depending for its effect on bitter, caustic, and often ironic language that is usually directed against an individual."
Irony: You take a train to avoid flying and during the trip your train is hit by an airplane.
Sarcasm: You comment to your seat mate as the plane approaches, "At least I saved money on the ticket."
One of my favorite examples of a sarcastic statement that reflected an ironic fact was when Churchill had a meeting with Hitler near the beginning of WWII. Hitler informed Churchill that Italy would be on Germany's side during the conflict. Churchill replied, "It's only fair. We had them during the last war."
But the way I keep Sarcasm and Irony separated is with this simple rule of thumb. Sarcasm springs from human wit and involves a biting or bitter sense of humor. Irony is a display of God's sense of humor.