The most common and most likely answer to this crossword clue is the 9 letter word EXTERNAL:
I've seen this crossword clue in The Guardian
E
X
T
E
R
N
A
L
:
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.
What does EXTERNAL: mean?
EXTERNAL: noun- (chiefly in the plural) The exterior; outward features or appearances.
- In the C programming language, a variable that is defined in the source code but whose value comes from some external source.
- Outside of something; on the exterior.
- Not intrinsic nor essential; accidental; accompanying; superficial.
- Foreign; relating to or connected with foreign nations.
- Away from the mesial plane of the body; lateral.
- Provided by something or someone outside of the entity (object, group, company etc.) considered.