The most common and most likely answer to this crossword clue is the 11 letter word COMMISERATE
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More clues leading to the result COMMISERATE
Buddy explains!

The straight part
We know that "show sympathy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case show sympathy = commiserate.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 COMMISERATE mean?
COMMISERATE adjective- Commiserating, pitying, lamentful
- To feel or express compassion or sympathy for (someone or something).
- (as the phrasal verb commiserate with) To sympathize; condole.
- To offer condolences jointly with; express sympathy with.