The most common and most likely answer to this crossword clue is the 5 plus 4 plus 5 plus 3 plus 7 plus 2 plus 3 plus 3 letter word WHICH CAME FIRST THE CHICKEN OR THE EGG
I've seen this crossword clue in The Guardian
W
H
I
C
H
C
A
M
E
F
I
R
S
T
T
H
E
C
H
I
C
K
E
N
O
R
T
H
E
E
G
G
Buddy explains!
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.