The most common and most likely answer to this crossword clue is the 4 letter word EACH
I've seen this crossword clue in Financial Times
E
A
C
H
More clues leading to the result EACH
Buddy explains!

The straight part
We know that "everyone" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case everyone = each.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 EACH mean?
EACH noun- (operations) An individual item: the least quantitative unit in a grouping.
- For one; apiece; per.
- Every one; every thing.