The most common and most likely answer to this crossword clue is the 5 letter word RATIO
I've seen this crossword clue in The Times
R
A
T
I
O
More clues leading to the result RATIO
- Proportion found in peroration
- “… passion acts upon the human mind in a — compounded of the acuteness of sense and constitutional heat”
- Heart of harangue in proportion
- Proportion grasped by adroit artist, looking back
- Limit short correspondence
- Share not quite in proportion
- Spanish banker clutching at relationship
- One going through most of shop’s correspondence
- One in a row about it recalled comparison
- 17:30 – maybe house destroyed in Nelson?
Buddy explains!

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 = ratio.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 RATIO mean?
RATIO noun- A number representing a comparison between two named things.
- The relative magnitudes of two quantities (usually expressed as a quotient).
- Short for ratio decidendi.
- The amount of comments to a post or other expression on social media relative to the number of likes.
- (social media) To respond to a post or message on social media in a greater number than the number of likes the post receives.