Surprised at bone spurs (nothing cut out) — that's being rude! (10)
I believe the answer is:
abruptness
'surprised at bone' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Maybe you can see an association between them that I don't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for abruptness that I've seen before include "Curtness" , "Curt rudeness" .)