Sincere ally hides grass (6)

I believe the answer is:

cereal

'grass' is the definition.
(I know that cereal is a type of grass)

'sincere ally hides' is the wordplay.
'hides' indicates a hidden word.
'CEREAL' is hidden within 'sincere ally'.

(Other definitions for cereal that I've seen before include "Breakfast dish" , "Rye, for example" , "output from harvest?" , "Eg, 5 Ac" , "Breakfast food made from grain" .)

I've seen this clue in The Irish Times.

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