Trendy partners for residents (7)
I believe the answer is:
inmates
'for residents' is the definition.
(inmate is a kind of resident)
'trendy partners' is the wordplay.
'trendy' becomes 'in' ('in' can mean fashionable).
'partners' becomes 'mates' ('mate' can be a synonym of 'partner').
'in'+'mates'='INMATES'
(Other definitions for inmates that I've seen before include "Ties man (anag.)" , "Inhabitants" , "Prisoners" .)