At home in New York, perhaps (8)
I believe the answer is:
astatine
'at' is the definition.
(synonyms)
'home in new york perhaps' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'in' is an insertion indicator.
'new york perhaps' becomes 'a state' (New York is a state).
'in' inserted within 'astate' is 'ASTATINE'.
(Other definitions for astatine that I've seen before include "Chemical element At" , "radioactive material" , "Atomic number 85" , "Rare element" , "Radioactive element" .)