Disreputable, in without a date, drooped (8)
I believe the answer is:
slouched
'drooped' is the definition.
(slouching is a kind of drooping)
'disreputable in without a date' is the wordplay.
'disreputable' becomes 'louche' (similar in meaning).
'in' means one lot of letters goes inside another.
'without a date' becomes 'sd' (I am not sure about this - if you are sure you should believe this answer much more).
'louche' put within 'sd' is 'SLOUCHED'.
Can you help me to learn more?
(Another definition for slouched that I've seen is " Walked or sat with droop".)