The most common and most likely answer to this crossword clue is the 9 letter word INITIATED
I've seen this crossword clue in The Daily Telegraph
I
N
I
T
I
A
T
E
D
More clues leading to the result INITIATED
- Hold back, it’s assumed, after one started
- Current delay is over – without it having started
- Launched popular appeal with new idea, consuming time
- Began by being made a member
- Introduced new dietitian
- Nick climbs around it after I set up
- One fool, one an old rocker brought into club?
- Launched popular appeal by one perked-up date
- I hold back, assuming it’s begun
Buddy explains!

The straight part
We know that "brought into club" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case brought into club = initiated.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 INITIATED mean?
INITIATED verb- To begin; to start.
- To instruct in the rudiments or principles; to introduce.
- To confer membership on; especially, to admit to a secret order with mysterious rites or ceremonies.
- To do the first act; to perform the first rite; to take the initiative.