The most common and most likely answer to this crossword clue is the 9 letter word FRIGHTENS
F
R
I
G
H
T
E
N
S
Buddy explains!
The straight part
We know that "Spooks" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case spooks = frightens.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 FRIGHTENS mean?
FRIGHTENS verb- To cause to feel fear; to scare; to cause to feel alarm or fright.