New 'No-fee Nurse' service was not expected (10)

I believe the answer is:

unforeseen

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'not expected' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs can occasionally define each other.

'new no-fee nurse service' is the wordplay.
'new' becomes 'n' (abbreviation as in New Testament NT).
'no' becomes 'O' (O resembles 0).
'service' indicates an anagram (I've seen 'serviced' mean this (to service can mean to repair)).
'n'+'o'+'fee'+'nurse'='nofeenurse'
'nofeenurse' anagrammed gives 'UNFORESEEN'.

'was' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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