Not a reticent bank employee (6)

I believe the answer is:

teller

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'bank employee' is the definition.
(as in a bank teller)

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

(Other definitions for teller that I've seen before include "Bank cashier or narrator of story" , "who worked on the hydrogen bomb" , "Narrator and bank clerk" , "Bank official to narrate the story" , "one gives relation" .)

I've seen this clue in The Irish Independent.

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