The most common and most likely answer to this crossword clue is the 7 letter word SCREECH
I've seen this crossword clue in The Guardian
S
C
R
E
E
C
H
More clues leading to the result SCREECH
- Cry that is about to reverberate endlessly
- Cry out, seeing loose weathered stones on front of church
- Terrifying sound rocks church
- Dreadful sound coming from disorganised creches
- Soprano about to appear in church choir with a shrill cry
- Terrifying sound rocks Switzerland
- Squeal emerging from loose rocks by church
- Harsh noise from church covered by ‘rock’, loosely
- Gulls collecting rubble by church
- Cry coming from church by loose rocks on side of mountain
Buddy explains!

The straight part
We know that "Dreadful sound" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dreadful sound = screech.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SCREECH mean?
SCREECH noun- A high-pitched strident or piercing sound, such as that between a moving object and any surface.
- A harsh, shrill cry, as of one in acute pain or in fright; a shriek; a scream.
- (Newfoundlander) Newfoundland rum.
- A form of home-made rye whiskey made from used oak rye barrels from a distillery.
- To make such a sound.
- To travel very fast, as if making the sounds of brakes being released