Drunk secures parking place (4)
I believe the answer is:
spot
'place' is the definition.
(I know that place can be written as spot)
'drunk secures parking' is the wordplay.
'drunk' becomes 'sot' (both can mean someone who drinks too much).
'secures' means one lot of letters goes inside another.
'parking' becomes 'p' (abbreviation on road signs).
'sot' going around 'p' is 'SPOT'.
(Other definitions for spot that I've seen before include "Pimple; place" , "Catch sight of - pimple" , "Small mark; see" , "Detect" , "Notice; mark" .)