Engrossed at home with old wine (6)
I believe the answer is:
intent
'engrossed' is the definition.
(synonyms)
'home with old wine' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'with' means one lot of letters go next to another.
'old wine' becomes 'tent' (I've seen this before. I am not sure about the 'old' bit.).
'in'+'tent'='INTENT'
'at' is the link.
Can you help me to learn more?
(Other definitions for intent that I've seen before include "Earnest, purpose" , "Firm - plan - steadfast - purpose" , "Bent on, determined to" , "Purpose, design" , "Mean to" .)