Critical mood (10)

I believe the answer is:

imperative

I believe this clue is a double definition.

'critical' is the first definition.
(thesaurus)

'mood' is the second definition.
(imperative mood is a kind of mood)

(Other definitions for imperative that I've seen before include "Requiring attention" , "Essential" , "Of vital importance, commanding" , "Extremely important" , "Crucial" .)

I've seen this clue in The Telegraph.

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