The most common and most likely answer to this crossword clue is the 11 letter word UNDERWRITER
I've seen this crossword clue in Financial Times
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More clues leading to the result UNDERWRITER
Buddy explains!
The straight part
We know that "Indemnity provided by one subscriber" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case indemnity provided by one subscriber = underwriter.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 UNDERWRITER mean?
UNDERWRITER noun- An entity assuming a financial risk.
- A person working for an insurance company who arranges and authorizes an insurance policy with a broker or insured.
- An entity undertaking to market newly issued securities.