Trespasser at home initially turned more disrespectful (8)
I believe the answer is:
intruder
'trespasser' is the definition.
('intruder' can be a synonym of 'trespasser')
'home initially turned more disrespectful' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'initially' suggests taking the first letters.
'more disrespectful' becomes 'ruder'.
The first letter of 'turned' is 't'.
'in'+'t'+'ruder'='INTRUDER'
'at' acts as a link.
(Other definitions for intruder that I've seen before include "One making uninvited entry" , "Butter in" , "Uninvited guest" , "Person who enters uninvited, perhaps a burglar" , "Unwelcome sort" .)