Officer allowed in river, uncovering parts of jugs (9)
I believe the answer is:
decollete
'uncovering parts of jugs' is the definition.
(decollete refers to a low neckline)
'officer allowed in river' is the wordplay.
'officer' becomes 'col' (I've seen this before).
'allowed' becomes 'let' (I've seen this before).
'in' is an insertion indicator.
'river' becomes 'dee' (River Dee).
'col'+'let'='collet'
'collet' going into 'dee' is 'DECOLLETE'.
(Other definitions for decollete that I've seen before include "baring chest" , "Of clothes, low-cut" , "exposing milk suppliers" , "Low cut" , "low-cut dress!" .)