The most common and most likely answer to this crossword clue is the 10 letter word PROPORTION
I've seen this crossword clue in Financial Times
P
R
O
P
O
R
T
I
O
N
More clues leading to the result PROPORTION
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The straight part
We know that "Correspondence" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case correspondence = proportion.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 PROPORTION mean?
PROPORTION noun- A quantity of something that is part of the whole amount or number.
- Harmonious relation of parts to each other or to the whole.
- Proper or equal share.
- The relation of one part to another or to the whole with respect to magnitude, quantity, or degree.
- A statement of equality between two ratios.
- The "rule of three", in which three terms are given to find a fourth.
- (chiefly in the plural) Size.
- To divide into proper shares; to apportion.
- To form symmetrically.
- To set or render in proportion.
- To correspond to.