Crossword Genius

Cast may need this, seeing a part rewritten (11*)

Ross

I believe the answer is:

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'cast may need this' is the definition.
The definition suggests a singular noun which matches the answer.

'seeing a part rewritten' is the wordplay.
'rewritten' indicates anagramming the letters.
'seeing'+'a'+'part'='seeingapart'
'seeingapart' is an anagram of 'GREASE PAINT'.

Can you help me to learn more?

(Other definitions for grease paint that I've seen before include "Theatrical make-up", "Actor's make-up".)

I've seen this clue in The Telegraph.