Film actress about to enter gala event (6)
I believe the answer is:
bacall
'film actress' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'about to enter gala event' is the wordplay.
'about' becomes 'ca' (short for circa).
'to enter' is an insertion indicator.
'gala event' becomes 'ball' (I've seen this in another clue).
'ca' going within 'ball' is 'BACALL'.
Can you help me to learn more?
(Other definitions for bacall that I've seen before include "Lauren -, The Big Sleep actress" , "Lauren --, US actress" .)