Slang for nothing back, nothing back, nothing... (5)
I believe the answer is:
lingo
'slang' is the definition.
(lingo can mean slang or jargon)
'nothing back nothing back nothing' is the wordplay.
'nothing' becomes 'nil' (eg nil is zero in football).
'back' is a reversal indicator.
'back' suggests the final letters (the letter at the back).
'nothing' becomes 'O' (looks like zero - 0).
The last letter of 'nothing' is 'g'.
'nil' backwards is 'lin'.
'lin'+'g'+'o'='LINGO'
'for' is the link.
(Other definitions for lingo that I've seen before include "Johnny Foreigner speaks one" , "Log in (anag.)" , "Unfamiliar language or jargon" , "means to communicate" , "Foreign language or dialect: jargon" .)