I come up with word ideas by thinking of the title first.
I always thought irony was an interesting word because it is different from iron the element despite being similarly spelled.
Irony showed up in the early sixteenth century. It stemmed from the classical Latin ironia, which in turn came from the Greek eironeia, where it was used to denote ignorance. It wasn’t until the seventeenth century that people started using it in the way that we currently know to be correct(as in, words used to express the opposite of their literal intention). And now three hundred years later, people are using it differently again!
Iron, the metal, comes from the Old English isaern, which came from the Proto Germanic isarnan, a word for holy metal (iron has always been thought to have magical qualities). If they kept that s in there, it would have remained unique, but during the time isarnan became iron, there was a shift in the Middle English language. The word underwent something called “rhotacism”, basically a change of a speech sound, usually an s or z to r (it’s even in the word since rho is the Greek letter for r).
So you can chalk this one up to a big old coincidence. I'd babble on more about this but I think NaNoWriMo is sapping up all my words.