Major acting role in Shaw play (7)

I believe the answer is:

barbara

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This clue might be a double definition.

'major acting role' is the first definition.
The definition suggests a singular noun which matches the answer.

'shaw play' is the second definition.
The definition suggests a singular noun which matches the answer.

'in' is the link.

Can you help me to learn more?

(Other definitions for barbara that I've seen before include "Castle, perhaps" , "girl" , "Dame - Cartland, English author" , "Major --, play by Shaw" , "female officer in SA" .)

I've seen this clue in The Guardian, The Telegraph and The Globe and Mail.

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