The most common and most likely answer to this crossword clue is the 6 plus 7 letter word FELLOW FEELING
F
E
L
L
O
W
F
E
E
L
I
N
G
More clues leading to the result FELLOW FEELING
Buddy explains!

The straight part
We know that "sympathy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sympathy = fellow feeling.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 FELLOW FEELING mean?
FELLOW FEELING noun- A sense of sympathy for, consideration of, or shared interests with one or more other human beings.