Quiet as foreign article's brought in (7)
I believe the answer is:
silence
'quiet' is the definition.
('silence' can be a synonym of 'quiet')
'as foreign article's brought in' is the wordplay.
'as' becomes 'since' (I've seen this before).
'foreign article' becomes 'le'.
'brought in' indicates putting letters inside.
'since' placed around 'le' is 'SILENCE'.
(Other definitions for silence that I've seen before include "Soundlessness" , "It is golden, they say" , "Nothing said" , "No talking" , "Absence of sound" .)