Present scoundrel with what's required by letter (7)
I believe the answer is:
current
'present' is the definition.
(similar in meaning)
'scoundrel with what's required by letter' is the wordplay.
'scoundrel' becomes 'cur' (cur can mean a despicable person).
'with' means one lot of letters go next to another.
'what's required by letter' becomes 'rent' (I can't explain this - if you can you should believe this answer much more).
'cur'+'rent'='CURRENT'
Can you help me to learn more?
(Other definitions for current that I've seen before include "Electrical flow" , "unlike these pieces" , "In general use; flow" , "Flow of air or water" , "Of the present time" .)