2024/0217 Ten Letter ... Er, WHAT?

[Calilasseia]

Won't spoil it for the two hours or so remaining (at least here in the UK anyway), but upon finally finding the ten letter word, my reaction was precisely that  - er, WHAT?

I pride myself on having a better than average knowledge of Classical Greek, but this one made me wonder who else is going to uncover this one, especially if they don't possess my educational benefits.

When the puzzle closes, I suspect several here may have something to say about this one ...

[blackrockrose]

I did get the 10-letter word, connecting it with a noun that I assume is common. But I agree that it's a rather unusual word, and there's a more common adjective from the same root that I'd use in preference to this one.

[Jacki]

I only found it by guessing how the letters would probably go together. I had to press on it to see the meaning. Another word added to my stupendous vocabulary 😄😄😄😄 Hee hee

[cmh]

As I have some vague connections to the Salvstion Army ,I am aware of the Euphonium as an instrument. It did not help me to get this word! Christine

[jem01060]

Although I got the word, I would not say it's common.