Waffle about central heating being dry (5)

I believe the answer is:

parch

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

'being dry' is the definition.
(I've seen this in another clue)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for parch that I've seen before include "Dehydrate" , "Make hot and dry" , "Make dry through heat" , "Get overheated" , "Cause to wither" .)

I've seen this clue in The Times and The Sunday Times.

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.