Cushy job at home acquired by firm (8)
I believe the answer is:
sinecure
'cushy job' is the definition.
(I've seen this before)
'home acquired by firm' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'acquired by' means one lot of letters goes inside another.
'firm' becomes 'secure' (similar in meaning).
'in' put into 'secure' is 'SINECURE'.
'at' acts as a link.
(Other definitions for sinecure that I've seen before include "Post requiring little work" , "Official job with little or no work" , "Very lucrative post" , "An office without work." , "position needing little effort" .)