Scoundrel approaching cleavage produces jet (7)
I believe the answer is:
current
'jet' is the definition.
'scoundrel approaching cleavage' is the wordplay.
'scoundrel' becomes 'cur' (I've seen this before).
'approaching' means one lot of letters go next to another.
'cleavage' becomes 'rent' (both can mean a tear or split in something).
'cur'+'rent'='CURRENT'
'produces' is the link.
(Other definitions for current that I've seen before include "Contemporary" , "unlike these pieces" , "Flow, of a river say" , "Flow of electricity" , "Up-to-date" .)