The other day I was telling one of my students that in the ye olde days, the lower categories of IQ scores were given names, in particular moron, imbecile and idiot. But I couldn’t remember the order.
In the process of searching for this information on the internet – the font of all knowledge – I discovered that moron comes from the word moros meaning dull. As opposed to oxy which means sharp.
So oxymoron means sharpdull.
Interesting.
If you don’t know what oxymoron means, I suggest you look it up or risk being recklessly categorised by pedantic dinner guests.
FYI, moron is one step above imbecile which is one step above idiot.
The Shrinking Head 
I feel the need to add an annoying thing that happens often when we use the term oxymoron. People reply with “That doesn’t make sense”.
Can we call this an Ironimoron? Please?
hahahahahhahahahaha yes. Let’s call Webster and ask if we can have it added to dictionary!