Home party is private (6)
I believe the answer is:
inside
'private' is the definition.
(similar in meaning)
'home party' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'party' becomes 'side' (eg a side or party in a contract).
'in'+'side'='INSIDE'
'is' is the link.
(Other definitions for inside that I've seen before include "Within - interior" , "Middle" , "locked up" , "Stomach etc - in prison?" , "Privileged" .)