Extinction Rebellion protesters are causing a bit of trouble in some of the big cities of the world at the moment.
The protesters are keen that the world and its inhabitants flourish, and they believe that climate change is a terminal threat to this happy outcome.
Now, whether the Extinction Rebellion protests are the right way to persuade those in authority to act, and whether a drive to reduce carbon emissions to zero by 2025 is the most effective way to stop climate change, I do not know. I'll just say that it would probably make any necessary progress easier if those on both sides would listen more generously to what the other side is saying.
Anyway, the British Prime Minister, Boris Johnson, recently called the protesters "uncooperative crusties". Boris is fond of an obscure word, and this one has become obscure very quickly as, in this meaning, it dates from only the 1980s.
The Oxford English Dictionary definition of crusty involves the words homeless, vagrant, young, begging, rough, matted, dreadlocked and unkempt, but this leaves out an important facet of crusty life style, which was that it was often driven by animal rights and environmental concerns.
So what's wrong with the word?
Well, as one of the Extinction Rebellion crowd pointed out, some of the protestors were librarians, doctors and teachers.
And if one of those is crusty it means something else entirely.
Word Not To Use Today: crusty/crustie. This word is probably derived from Crust Punk. The crust is the line of grime caused by not having access to baths. As Mr Johnson will know, the word crust comes from the Latin word crūsta, which means hard surface, rind or shell (and is therefore related to the word crustacean).