Park closing before the break of day is lit up (9)
I believe the answer is:
plastered
'is lit up' is the definition.
(thesaurus)
'park closing before the break of day' is the wordplay.
'park' becomes 'P' (abbreviation as on an automatic car's gear lever).
'closing' becomes 'last' (similar in meaning).
'before' becomes 'ere' (poetic term).
'the break of day' becomes 'd' (I've seen this in other clues).
'p'+'last'+'ere'+'d'='PLASTERED'
(Other definitions for plastered that I've seen before include "Drunk (as a ceiling or wall may be)" , "like walls and ceilings?" , "wasted" , "Pickled" , "Like member in cast" .)