Leader of strike with nurse: it’s shocking (6)

I believe the answer is:

scarer

'it's shocking' is the definition.
(something that scares or shocks)

'leader of strike with nurse' is the wordplay.
'leader of' indicates taking the first letters.
'with' says to put letters next to each other.
'nurse' becomes 'carer' (I've seen this before).
The first letter of 'strike' is 's'.
's'+'carer'='SCARER'

(Another definition for scarer that I've seen is " a terrifying sort".)

I've seen this clue in The Guardian.

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