The most common and most likely answer to this crossword clue is the 9 letter word SO-AND-SO
I've seen this crossword clue in Independent
S
O
-
A
N
D
-
S
O
More clues leading to the result SO-AND-SO
- Pain accordingly doubled
- Unpleasant type, whatshisname?
- Child comes across a gong, not a nice sort
- Piece of work announced: instructions for gardener, seamstress?
- Nothing special and, at heart, a bit of a git
- Cursed individual barking orders at seamstress?
- What’s-his-name is a right pain in the behind
- Annoying person‘s kid collecting a medal
- No great shakes going around with this person
- Disliked person sadly said “I must be leaving soon”
Buddy explains!

The straight part
We know that "Annoying person" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case annoying person = so-and-so.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 SO-AND-SO mean?
SO-AND-SO noun- A placeholder name for a person or thing, used when a name is not known; a generic name.
- Some thing or things.
- Used for epithets such as SOB, bastard, etc..