This is why broadcast is blasphemy (6)

I believe the answer is:

heresy

I'm a little stuck... Click here to teach me more about this clue!

'blasphemy' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for heresy that I've seen before include "Opinion opposed to orthodox belief" , "Opinion contrary to orthodox belief" , "Doctrine that differs from the orthodox position" , "Belief that rejects the orthodox tenets of a religion" , "unorthodox views" .)

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.