Still turning up in Montmartre nightlife (5)
I believe the answer is:
inert
'still' is the definition.
(not moving)
'turning up in montmartre nightlife' is the wordplay.
'turning up' says the letters should be written backwards.
'in' indicates a hidden word.
'treni' is hidden in the letters of 'montmartre nightlife'.
'treni' written backwards gives 'INERT'.
(Other definitions for inert that I've seen before include "Lifeless, without power to move or act" , "Indolent - unreactive" , "Sluggish, inactive" , "Passive, immobile" , "Chemically unreactive" .)