The most common and most likely answer to this crossword clue is the 8 letter word AVAILING
I've seen this crossword clue in The Daily Telegraph
A
V
A
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Buddy explains!

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 AVAILING mean?
AVAILING verb- To turn to the advantage of.
- To be of service to.
- To promote; to assist.
- To be of use or advantage; to answer or serve the purpose; to have strength, force, or efficacy sufficient to accomplish the object.
- To provide; to make available.
- Effect in achieving a goal or aim; purpose, use
- Efficacious.