The most common and most likely answer to this crossword clue is the 7 letter word MOURNER
M
O
U
R
N
E
R
More clues leading to the result MOURNER
- One in black, Parisian mother briefly hugs old vessel
- More troubled about location of ashes? One might be
- Half-hearted runner’s head dropping – Farah starts keener
- Repository for ashes found in Rome moved person attending funeral
- Bereaved person more worried about location of ashes?
- Person in Black Sea abroad catches old vessel
Buddy explains!

The straight part
We know that "One in black" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one in black = mourner.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 MOURNER mean?
MOURNER noun- Someone filled with or expressing grief or sadness, especially over a death; someone who mourns.