Be outside a quiet prison (8)
I believe the answer is:
bastille
'prison' is the definition.
(I've seen this before)
'be outside a quiet' is the wordplay.
'outside' means one lot of letters goes inside another.
'quiet' becomes 'still' (still is a kind of quiet).
'a'+'still'='astill'
'be' enclosing 'astill' is 'BASTILLE'.
(Other definitions for bastille that I've seen before include "Old Parisian prison" , "Parisian fortress" , "Fortress in Paris" , "Paris prison stormed in 1789 ad." , "Ballet is about notorious prison in Paris" .)