1. The use of words to express something other than and especially the opposite of the literal meaning
2.an outcome of events contrary to what was, or might have been, expected.
In sense, irony is just the opposite of what you think will happen.
Irony can be found anywhere you look however. Like the Titanic which was said to have been 100% unsinkable and then sunk on its first expedition. It is the exact opposite of what you expected.