The most common and most likely answer to this crossword clue is the 3 plus 5 plus 3 plus 3 plus 4 letter word THE WORLD AND HIS WIFE
I've seen this crossword clue in The Guardian
T
H
E
W
O
R
L
D
A
N
D
H
I
S
W
I
F
E
Buddy explains!
The straight part
We know that "everybody" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case everybody = the world and his wife.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.