The most common and most likely answer to this crossword clue is the 9 letter word HEADLINER
I've seen this crossword clue in The Guardian
H
E
A
D
L
I
N
E
R
More clues leading to the result HEADLINER
- Ship that’s passed cape makes major turn
- Top act, male, extremely assured on ship
- Cast her in lead?
- Dancing in reel, had to be star attraction
- Act topping bill I learned trashed hotel previously
- The man Ireland changed is top of the bill
- Person in charge on ship is a star
- Captain ship, one making the news
- The woman’s embracing Daniel, fantastic performer with top billing
- Top act cruise ship put on kept snorting drug
Buddy explains!

The straight part
We know that "Cast her in lead" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cast her in lead = headliner.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 HEADLINER mean?
HEADLINER noun- The headlining band or performer at a concert or similar event; the best-known and first billed musician, comedian, etc., often performing as the final act of the evening.
- The interior fabric covering the roof of a vehicle.