The most common and most likely answer to this crossword clue is the 9 letter word BECQUEREL
I've seen this crossword clue in Financial Times
B
E
C
Q
U
E
R
E
L
More clues leading to the result BECQUEREL
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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 BECQUEREL mean?
BECQUEREL noun- In the International System of Units, the derived unit of radioactive activity; the activity of a quantity of radioactive material in which one nucleus decays per second. Symbol: Bq