Estrangement from a people embracing untruth (10)
I believe the answer is:
alienation
'estrangement' is the definition.
(synonyms)
'a people embracing untruth' is the wordplay.
'people' becomes 'nation' ().
'embracing' means one lot of letters goes inside another.
'untruth' becomes 'lie' (lie is a kind of untruth).
'a'+'nation'='anation'
'anation' going around 'lie' is 'ALIENATION'.
'from' acts as a link.
(Other definitions for alienation that I've seen before include "State of feeling isolated" , "Disunity" , "Brecht's effect" , "Turning" , "Estrangement" .)