Founder of NSYNC vocalised after Justin finally left (4)

I believe the answer is:

sink

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

'founder' is the definition.
(I know that founder is a more specific form of sink)

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for sink that I've seen before include "Scene of iniquity or washing up" , "Basin - scupper" , "Washbasin" , "Subside" , "Washing facility" .)

I've seen this clue in The Guardian.

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