They may fight though they're not boxers (8)
I believe the answer is:
terriers
'boxers' is the definition.
The definition and answer can be both animals as well as being plural nouns.
Maybe there's an association between them I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for terriers that I've seen before include "Airedales, for example" , "Small short-bodied breeds of dogs" , "Part-time soldiers" , "eg Skye, Cairn and 18" .)