Junk emails (4)
I believe the answer is:
spam
'junk emails' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for spam that I've seen before include "Tinned meat - unwanted email" , "(Send) junk mail" , "Unwanted communication" , "net on junk? On the contrary" , "Tinned processed meat" .)