The most common and most likely answer to this crossword clue is the 9 letter word ESPIONAGE
I've seen this crossword clue in The Daily Telegraph
E
S
P
I
O
N
A
G
E
More clues leading to the result ESPIONAGE
- English person of wisdom outside very good on secret assignments?
- Age ponies developed intelligence
- Intelligence shown by ponies about to mature
- ESP in later years to keep old in hush-hush work
- Work of agents to promote say a top model, nothing less
- Sea pigeon used for undercover work
- English wise to imprison detective working in spying
- Page is one trained for secret work
- Secretly watching sea pigeon flying
- Agent’s work?
Buddy explains!
The straight part
We know that "secret work" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case secret work = espionage.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 ESPIONAGE mean?
ESPIONAGE noun- The act or process of learning secret information through clandestine means.