Flash singlet, belted (7)

I believe the answer is:

glisten

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

'flash' is the definition.
(glisten is a kind of flash)

'singlet belted' is the wordplay.
'singlet' can be anagrammed to 'GLISTEN'.
Though, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for glisten that I've seen before include "Shine or sparkle wetly" , "gloss" , "Let sing (anag) -- shine" , "look bright" , "'Shine, as if wet (7)'" .)

I've seen this clue in The Times.

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