The most common and most likely answer to this crossword clue is the 10 letter word COMPLEXITY
I've seen this crossword clue in The Guardian
C
O
M
P
L
E
X
I
T
Y
Buddy explains!

The straight part
We know that "Elaboration" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case elaboration = complexity.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 COMPLEXITY mean?
COMPLEXITY noun- The state of being complex; intricacy; entanglement.
- That which is and renders complex; intricacy; complication.