Unfashionable, untruthful and remote (8)
I believe the answer is:
outlying
'remote' is the definition.
(thesaurus)
'unfashionable untruthful' is the wordplay.
'unfashionable' becomes 'out' ('out' can be a synonym of 'unfashionable').
'untruthful' becomes 'lying' ('lying' can be similar in meaning to 'untruthful').
'out'+'lying'='OUTLYING'
'and' is the link.
(Other definitions for outlying that I've seen before include "Away from the middle" , "On the exterior" , "remote area" , "Remote from the centre" .)