At home, engaged in safe cushy job (8)
I believe the answer is:
sinecure
'cushy job' is the definition.
(I've seen this in another clue)
'at home engaged in safe' is the wordplay.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'engaged in' means one lot of letters goes inside another.
'safe' becomes 'secure' (synonyms).
'in' inserted within 'secure' is 'SINECURE'.
(Other definitions for sinecure that I've seen before include "Paid job with minimal work - insecure (anag)" , "Job for easy money" , "Post requiring little work" , "Informally, a bobby's job" , "Paid job involving little or no work" .)