A tripe product not endorsed by law (6)
I believe the answer is:
pirate
'law' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'a tripe product not endorsed' is the wordplay.
'a tripe' anagrams to 'PIRATE'.
Though, I am unsure how the anagram is indicated.
'by' is the link.
Can you help me to learn more?
(Other definitions for pirate that I've seen before include "Criminal on the high seas" , "Captain Hook, say" , "Sea raider" , "Robber on the high seas" , "plagiarist" .)