The most common and most likely answer to this crossword clue is the 7 letter word FEARFUL
I've seen this crossword clue in The Times
F
E
A
R
F
U
L
Buddy explains!

The straight part
We know that "Afraid" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case afraid = fearful.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 FEARFUL mean?
FEARFUL adjective- Frightening.
- Tending to fear; timid.
- Terrible; shockingly bad.
- Frightened; filled with terror.
- Extremely; fearfully.