Sees gal in dance forever young (7)

I believe the answer is:

ageless

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'forever young' is the definition.
(not aging)

'sees gal in dance' is the wordplay.
'sees gal' can be anagrammed to 'AGELESS'.
But, I'm not clear how the anagram is indicated.

Can you help me to learn more?

(Other definitions for ageless that I've seen before include "Enduring" , "Always youthful" , "Classic" , "Never growing old" , "Perpetually young" .)

I've seen this clue in The Sun.

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