"Irony (from the Ancient Greek εἰρωνεία eirōneía, meaning hypocrisy, deception, or feigned ignorance) is a literary or rhetorical device, in which there is an incongruity or discordance between what one says or does and what one means or what is generally understood." (Definition from Wikipedia)

 

Or simply its meant the use of words to express or convey something different from and often opposite to its literal meaning, and we got a very good example to show u guys what is Irony meant btw (see below):