Fireplace that's tremendous, so we hear (5)

I believe the answer is:

grate

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

'fireplace' is the definition.
(grate can mean a fireplace)

I cannot understand how the rest of the clue works.

(Other definitions for grate that I've seen before include "Barred framework" , "Irritate - rasp - fireplace" , "Grind (cheese)" , "Make a harsh rasping sound" , "Shred - jar" .)

Want a hint initially instead of a full solution? Install my app