The most common and most likely answer to this crossword clue is the 9 letter word DEBUTANTE
I've seen this crossword clue in The Daily Telegraph
D
E
B
U
T
A
N
T
E
More clues leading to the result DEBUTANTE
- Society girl in Underground, sent up to visit poet
- Writer holding Underground up for one making her first appearance
- One coming out of underground uprising captured by poet
- Poet holding pipe recalled young lady coming out
- Be taunted about a young socialite
- Transport system held up by poet and young lady
- 1 down holding container up for young socialite
- Woman making first appearance badly taunted about errand boy, initially
- Dame lacking guts, though bet she’s introduced to society
- Writer welcomes TV that’s promoted society girl
Buddy explains!

The straight part
We know that "society girl" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case society girl = debutante.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 DEBUTANTE mean?
DEBUTANTE noun- A young woman who makes her first formal appearance in society.
- A female debutant, especially in sport and entertainment.