The most common and most likely answer to this crossword clue is the 6 letter word REVERS
I've seen this crossword clue in The Daily Telegraph
R
E
V
E
R
S
More clues leading to the result REVERS
Buddy explains!

The straight part
We know that "Lapel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lapel = revers.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 REVERS mean?
REVERS noun- A lapel of a garment, turned back to show the reverse side.