Set up home close to Boris? Unlikely (7)
I believe the answer is:
install
'set up' is the definition.
(synonyms)
'home close to boris? unlikely' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'close to' suggests the final letters (the 'close' to the word).
'unlikely' becomes 'tall' (as in a tall tale).
The final letter of 'boris' is 's'.
'in'+'s'+'tall'='INSTALL'
(Other definitions for install that I've seen before include "Set up, ready for use" , "Emplace" , "Put in place ready for use" , "Lodge" , "Place in position, establish" .)