Not all fire alarms are genuine (4)

I believe the answer is:

real

'genuine' is the definition.
(I know that genuine can be written as real)

'not all fire alarms are' is the wordplay.
'not all' indicates a hidden word (only some of the letters).
'REAL' is hidden within 'fire alarms are'.

(Other definitions for real that I've seen before include "Actual, not imagined" , "Physically existing" , "Happening in actuality" , "Existing, not imaginery" , "Certainly no counterfeit" .)

I've seen this clue in The Irish News.

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