He's no gentleman, perhaps, unrobed (7)
I believe the answer is:
bounder
'he's no gentleman' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'perhaps unrobed' is the wordplay.
'perhaps' is an anagram indicator.
'unrobed' anagrammed gives 'BOUNDER'.
Can you help me to learn more?
(Other definitions for bounder that I've seen before include "Dishonourable man (dated colloq.)" , "A cad - or a kind of jumper" , "The skipper" , "A hop-along cad?" , "despicable man" .)