The most common and most likely answer to this crossword clue is the 4 letter word ELAN
I've seen this crossword clue in The Guardian
E
L
A
N
More clues leading to the result ELAN
- Network following leader with eccentric style
- New beer knocked back in style
- Antelope's endless spirit
- Dash put in pastureland
- African animal's out of delta in dash
- Antelope’s endless combination of style and vigour
- Spirit overcome by melancholy
- Feel anxious, hampering style
- Style arising in Havana, legendary
- French polish made partly from melanin
Buddy explains!

The straight part
We know that "French polish" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case french polish = elan.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 ELAN mean?
ELAN noun- Ardor or zeal inspired by passion or enthusiasm.