One European sacked from job as health worker (5)
I believe the answer is:
carer
'health worker' is the definition.
The definition suggests a singular noun which matches the answer.
'one european sacked from job' is the wordplay.
'one european' becomes 'e' (abbreviation e.g. EU).
'sacked from' indicates named letters should be taken away.
'job' becomes 'career' (I've seen this before).
'career' with 'e' removed is 'CARER'.
'as' is the link.
Can you help me to learn more?
(Other definitions for carer that I've seen before include "One with responsibility for dependent person" , "Responsible person" , "Attendant in nursing home" , "One looking after sick" , "One looking after another" .)