Merkel of moviedom (3)
I believe the answer is:
una
'merkel of moviedom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for una that I've seen before include "of satellite with no sides" , "- Stubbs, Eng. actress" , "She's one in Italy." , "Diego's one" , "lady" .)