Squalid type briefly performed (6)
I believe the answer is:
sordid
'squalid' is the definition.
(synonyms)
'type briefly performed' is the wordplay.
'type' becomes 'sort' (I've seen this before).
'briefly' means to remove the last letter.
'performed' becomes 'did' ('do' can be a synonym of 'perform').
'sort' with its last letter taken off is 'sor'.
'sor'+'did'='SORDID'
(Other definitions for sordid that I've seen before include "Filthy - base" , "Squalid - base" , "Squalid and depraved" , "Squalid and disgusting" , "'Sleazy, squalid (6)'" .)