Girl endlessly radiant after somersault (4)

I believe the answer is:

olga

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This might be a double definition.

'girl' is the first definition.

'endlessly radiant after somersault' is the second definition.
The definition suggests a singular noun which matches the answer.

Can you help me to learn more?

(Other definitions for olga that I've seen before include "Russian girl's name, anagram of ..." , "Lady" , "Could be Russian girl" , "Slavic girl's name" .)

I've seen this clue in The Guardian.

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