Rhino, say, catches horny extremities in cramped movement (9)
I believe the answer is:
pachyderm
'rhino' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pachyderm that I've seen before include "Insensitive sort" , "Large hoofed animal with a very thick skin" , "Thick-skinned mammal like elephant" , "Thick-skinned beast, such as a rhino" , "Elephant, hippo etc" .)