The most common and most likely answer to this crossword clue is the 13 letter word CONFIGURATION
I've seen this crossword clue in The Guardian
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More clues leading to the result CONFIGURATION
Buddy explains!
The straight part
We know that "Layout" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case layout = configuration.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 CONFIGURATION mean?
CONFIGURATION noun- Form, as depending on the relative disposition of the parts of a thing's shape; figure; form factor.
- Relative position or aspect of the planets; the face of the horoscope, according to the relative positions of the planets at any time.
- The way things are arranged or put together in order to achieve a result.
- The arrangement of electrons in an atom, molecule, or other physical structure like a crystal.
- A finite set of points and lines (and sometimes planes), generally with equal numbers of points per line and equal numbers of lines per point.