Crossword Genius

Fish sauce -- at last there's a set of rules (4)

Ross

I believe the answer is:

code

'a set of rules' is the definition.
(I've seen this before)

'fish sauce at last' is the wordplay.
'fish' becomes 'cod' (cod is a kind of fish**).
'at last' suggests the final letters.
The final letter of 'sauce' is 'e'.
'cod'+'e'='CODE'

'there's' acts as a link.

(Other definitions for code that I've seen before include "System of signals" , "(Computer) programming instructions" , "Cryptographic system" , "It may be impossible to read" , "Specially devised system of words, as by Morse" .)

I've seen this clue in The Telegraph.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.