Muddle up (6)

I believe the answer is:

garble

(Other definitions for garble that I've seen before include "Confuse (a message)" , "jumble" , "Corrupt" , "Transmit in distorted version" , "distorted transmission" .)

I've seen this clue in The Guardian.

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.