prove me wrong

 I am currently teaching high school English.  As such figures of speech keep popping up.  The English class I teach happens to be for speakers of languages other than English.  Mostly Spanish- my French study has not come in handy so far. I was (trying) to explain denotation, connotation, and collocation just the other day.  

Some linguist I know threw out the phrase "collocation clash" today.  I've never heard of it.  He said it was like an oxymoron- when two contradictory words or ideas are put together like 'jumbo shrimp' or 'humblebrag.'

Then I thought to myself- 'Self- why would there be another word for the same thing? Why not just call it an oxymoron-because let's face it it's fun to say 'oxymoron.''

So- I looked up collocation clash to find that it is not an oxymoron, but also not clearly defined- I  concluded that it is -instead words or ideas put together that native speakers generally don't put together.  My example was 'holy cow' is a collocation because we find those two words together and it is expected and ordinary.  If I said, 'holy heifer!' - as a native English speaker you would know the intention, but it's not a collocation, because we don't usually use those words together.  

Therefore- 'holy heifer' is a collocation clash- 'holy cow' is a collocation, and I tell you in 'loud whisper' that Collocation clashes are not oxymorons.