The most common and most likely answer to this crossword clue is the 8 letter word CALVADOS
I've seen this crossword clue in Financial Times
C
A
L
V
A
D
O
S
More clues leading to the result CALVADOS
- Apple brandy and soda served up after Calvin’s dropped in
- Drink up after reformer drops in for a brandy
- Mostly free ice and fizzy drink over brandy
- Roughly, boy drinks very, very big brandy
- Sad vocal remixed with Gallic spirit
- Mr Klein drops in, sending back soda for something stronger
- Two states having parties for department
- Sad, vocal, befuddled? That’ll be the brandy
- One of 24 religious reformer’s lost in troubles
- Brandy very appealing initially, as cold unfortunately outside
Buddy explains!

The straight part
We know that "brandy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case brandy = calvados.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 CALVADOS mean?
CALVADOS noun- An apple brandy made in Normandy, France.
- A glass of this spirit.