Crikey, a French horn! (3)

I believe the answer is:

cor

I believe this clue is a double definition.

'crikey' is the first definition.
(both are expressions of surprise)

'a french horn' is the second definition.
('horn' in French)

(Other definitions for cor that I've seen before include "Blimey" , "Surprised expression" , "Gosh" , "Expression of surprise" .)

I've seen this clue in the Evening Standard.

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