What's left if there isn't a hint? (8)

I believe the answer is:

reminder

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

'a hint?' is the definition.
(I've seen this before)

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

(Other definitions for reminder that I've seen before include "Memo - souvenir" , "Memento" , "Aide-mmoire" , "Memory refresher" , "Prompt, memory jog" .)

I've seen this clue in The Independent.

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