Irony = "Despite"

Irony is a tricky subject. We find it difficult to explain and harder to define. We understand it well enough to point out when a situation is ironic, but are hard-pressed to find words for it.

Well, today is your lucky day, because I can define irony in a single word: Despite.

Irony is when something happens, even though it shouldn't have. That is the same situation that we use the word 'despite'.

I didn't have a pen, despite the fact that I sell pens for a living.  That's ironic.
My house is filthy, despite the fact that I clean houses for a living.  Again, ironic.
My friend committed suicide, despite being a professional grief counselor.  Still ironic; also terribly sad.

You could also define irony with the word 'although' by flipping the sentence order.

Although I sell pens for a living, I didn't have a pen.  Ironic, that is.
Although I clean houses for a living, my house is filthy.  Ironic, again.

I'm skipping the third one because it doesn't need to be twisted around. It's twisted enough, already.

Anyway, irony. It's not that scary or complicated after all. It's just a fancy-sounding word that can be defined with a simple-sounding word. Go forth and spread the word.