Do keep quiet during work (7)
I believe the answer is:
shindig
'do' is the definition.
(I've seen this before)
'keep quiet during work' is the wordplay.
'keep quiet' becomes 'sh' (as in shushing someone).
'during' becomes 'in' (e.g. during February means in February).
'work' becomes 'dig' (digging is a kind of working).
'sh'+'in'+'dig'='SHINDIG'
(Other definitions for shindig that I've seen before include "Bash" , "Big lively party (colloq.)" , "Large, lively party" , "Lively party, knees-up" , "Rumpus" .)