The most common and most likely answer to this crossword clue is the 9 letter word FORTUNATE
I've seen this crossword clue in Financial Times
F
O
R
T
U
N
A
T
E
More clues leading to the result FORTUNATE
- Lucky having strength to catch big fish
- Lucky, finding strength to catch fish
- Blessed with strength to catch fish
- Lucky on account of letter to the head being withdrawn
- Adversary keeps playing truant – that’s lucky
- Lucky yet strange turn o’ fate
- Lucky swimmer, showing strength on the outside
- Blessed with a lot of money — about a ton!
- 2 Lucky to change a rut often
- Beef or tuna teatime sandwiches, heaven-sent
Buddy explains!

The straight part
We know that "Lucky" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lucky = fortunate.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 FORTUNATE mean?
FORTUNATE adjective- Auspicious.
- Happening by good luck or favorable chance.
- Favored by fortune.