Eldest in trouble took a job with a major employer (8)

I believe the answer is:

enlisted

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'took a job with a major employer' is the definition.
I can't judge whether this definition defines the answer.

'eldest in trouble' is the wordplay.
'trouble' indicates an anagram.
'eldest'+'in'='eldestin'
'eldestin' is an anagram of 'ENLISTED'.

Can you help me to learn more?

(Other definitions for enlisted that I've seen before include "Signed up" , "Persuaded to serve" , "Employed" , "Lower ranks in US army" , "Recruited" .)

I've seen this clue in the Irish Times (Crosaire) and the Irish Times.

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