Lay bare a street reprobate (5)
I believe the answer is:
strip
'lay bare' is the definition.
(synonyms)
'a street reprobate' is the wordplay.
'a street' becomes 'st' (abbreviation).
'reprobate' becomes 'rip' (informal term for a fraud).
'st'+'rip'='STRIP'
(Other definitions for strip that I've seen before include "Remove clothes, just a sliver" , "Take off clothing" , "Kind of lighting" , "Peel; long narrow piece" , "Lay bare" .)