The most common and most likely answer to this crossword clue is the 5 letter word JAPAN
I've seen this crossword clue in Independent
J
A
P
A
N
More clues leading to the result JAPAN
- Varnish judge used on a vessel
- Consent from Germany to criticise its wartime ally
- Varnish jack and ace before card game’s over
- Stuff mostly found on a container of varnish
- Dad supports German agreement with neutral country
- Country where first of two vessels is docked
- Hard black varnish containers – one not closed
- A person’s first month outside country
- Polish man comes out of palanquin
Buddy explains!

The straight part
We know that "varnish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case varnish = japan.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 JAPAN mean?
JAPAN noun- A hard black enamel varnish containing asphalt.
- Lacquerware.
- To varnish with japan.