Battle dress with heraldic associations! (4,2,4)
I believe the answer is:
coat of arms
'with heraldic associations' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'battle dress' is the wordplay.
I cannot really see how this works, but
'dress' could be 'coat' (coating is a kind of dressing) and 'coat' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for coat of arms that I've seen before include "Badge" , "Sign of a family" , "Official device" , "Heraldic shield" , "Armorial bearings" .)