Canon listing all works primarily (3)
I believe the answer is:
law
'canon' is the definition.
(canon can mean a law or principle)
'listing all works primarily' is the wordplay.
'primarily' says to take the initial letters.
The initial letters of 'listing all works' is 'LAW'.
(Other definitions for law that I've seen before include "Body of rules of conduct for a society" , "Collection of rules imposed by authority" , "'Possession is nine points of the ...'" , "Collection of rules for a society" , "at 16 down [MAN UNITED]" .)