Genuine house, home to a bird (6)
I believe the answer is:
honest
'genuine' is the definition.
('honest' is associated in meaning with 'genuine')
'house home to a bird' is the wordplay.
'house' becomes 'ho' (abbreviation for house).
'home to a bird' becomes 'nest' (I've seen this before).
'ho'+'nest'='HONEST'
(Other definitions for honest that I've seen before include "really!" , "Truthful in manner" , "Free from guile" , "Honourable, true" , "Not lying" .)