The most common and most likely answer to this crossword clue is the 7 letter word ATTACHE
I've seen this crossword clue in Independent
A
T
T
A
C
H
E
More clues leading to the result ATTACHE
- Diplomat with strong desire to drink? The opposite!
- A pain keeping dry for diplomat
- Diplomat committed to seeing someone shortly
- Empty threat in a long sort of case
- Diplomat’s encouragement of revolutionary?
- Diplomatic official cheers up, overlooking facial feature
- Diplomat’s secured missing diamonds
- Mostly charge male in this case
- Germany abandoned tied diplomat
- Criticism curtailed by ambassador — or other member of embassy?
Buddy explains!

The straight part
We know that "Diplomatic official" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case diplomatic official = attache.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 ATTACHE mean?
ATTACHE noun- A diplomatic officer, usually one who plays a specific role.