The most common and most likely answer to this crossword clue is the 7 plus 3 plus 5 letter word PERSONA NON GRATA
I've seen this crossword clue in Independent
P
E
R
S
O
N
A
N
O
N
G
R
A
T
A
More clues leading to the result PERSONA NON GRATA
- Unwelcome sort, diplomatically asked to leave
- One to ignore grandma has struck arrogant pose outside
- No! Paragons aren’t cast as undesirable!
- Great rap moves involving boy, soon an outcast
- Undesirable article in baroque contents of Brontë Parsonage
- Unwelcome presence of stranger, OAP off to hide soon
- Theatre upset with composition involving new organ, sadly undesirable
- One unwelcome rant on parsonage – nasty
- He’s blackballed Roman chap, soon good grass gets answer
- Undesirable and mostly arrogant, opens up
Buddy explains!
The straight part
We know that "Unwelcome presence" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unwelcome presence = persona non grata.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.