Girl serenaded endlessly? (6)

I believe the answer is:

serena

I'm a little stuck... Click here to teach me more about this clue!

'girl serenaded endlessly?' is the definition.
I can't judge whether this defines the answer.

'girl serenaded endlessly?' is the wordplay.
'girl' becomes 'ser' (I can't justify this - if you can you should give a lot more credence to this answer).
'endlessly?' indicates the central letters (I've seen 'endlessly' mean this (the ends of the words are removed)).
The middle letters of 'serenaded' are 'ena'.
'ser'+'ena'='SERENA'

Can you help me to learn more?

(Other definitions for serena that I've seen before include "Woman" , "-- Williams, tennis star" .)

I've seen this clue in the Evening Standard.

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