The most common and most likely answer to this crossword clue is the 9 letter word FIREWATER
I've seen this crossword clue in Financial Times
F
I
R
E
W
A
T
E
R
More clues leading to the result FIREWATER
- Incompatible ingredients in strong spirit
- One swallowing a tree drinking western liquor!
- Get rid of server dropping one drink that’s strong
- Spirit elements
- Two classical elements in whisky
- Strong liquor, whiskey drunk by one downing tree?
- Two original elements in schnapps, perhaps
- Sack restaurant worker nicking one strong drink
- Strong drink giving circus performer change of bearing
Buddy explains!

The straight part
We know that "drink that’s strong" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case drink that’s strong = firewater.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 FIREWATER mean?
FIREWATER noun- High-proof alcohol, especially whiskey (especially in the context of its sale to or consumption by Native Americans).
- High-temperature hydraulic condensate discharged from industrial boilers.
- Water for use in firefighting.