Glower from club user initially barred (5)

I believe the answer is:

ember

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'glower' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for ember that I've seen before include "Material in dying fire" , "Glowing coal; type of goose" , "Glowing, smouldering piece of coal or wood" , "One smouldering" , "Glower" .)

I've seen this clue in The Sun and The Telegraph.

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