The most common and most likely answer to this crossword clue is the 3 letter word VIS
V
I
S
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The straight part
We know that "With regard to" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with regard to = vis.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 VIS mean?
VIS noun- Force; energy; might; power.
- A member of the peerage, above a baron but below a count or earl.
- Any of various nymphalid butterflies of the genus Tanaecia. Other butterflies in this genus are called earls and counts.
- A Burmese unit of measure for weight, approximately 1.63293 kilograms (3.6 pounds).