The Spanish involved in indication of cloying sentimentality (7)

I believe the answer is:

treacle

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'cloying sentimentality' is the definition.
(I've seen this in another clue)

I don't understand the rest of the clue.

(Other definitions for treacle that I've seen before include "Syrup-like substance" , "Electra (anag)" , "Sweet, black viscous substance" , "cloying stuff" , "Dark viscous 11" .)

I've seen this clue in the Sydney Morning Herald.

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