The most common and most likely answer to this crossword clue is the 3 plus 5 letter word LAY WASTE
L
A
Y
W
A
S
T
E
More clues leading to the result LAY WASTE
- To ravage always wrong, note
- Ruin song with a short dance sequence
- Put rubbish in sack
- Destroy note, always rewritten beforehand
- Sack women on non-professional new seat
- Desolate year existed in past
- Destroy left-overs after carpet-fitting?
- Desolate amateur shrink
- Always drunk, leading those disheartened to ruin
- Ruin as finally Kennedy was brought in dead
Buddy explains!

The straight part
We know that "Desolate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case desolate = lay waste.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.