One watching Casualty in US chasing celebrity (6)

I believe the answer is:

starer

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'one watching' is the definition.
The definition suggests a singular noun but the answer is not.

'casualty in us chasing celebrity' is the wordplay.
'casualty in us' becomes 'ER' (emergency room, US equivalent to casualty dept.).
'chasing' is a charade indicator (letters next to each other) (some letters chase after others).
'celebrity' becomes 'star' (a star is a celebrity or famous person).
'er' after 'star' is 'STARER'.

Can you help me to learn more?

(Other definitions for starer that I've seen before include "Person gawping" , "looker" , "keen viewer" , "One gazing intently" .)

I've seen this clue in The Times.

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