Pass up plans for processed meat (4)
I believe the answer is:
spam
'processed meat' is the definition.
(I've seen this before)
'pass up plans' is the wordplay.
'pass up' shows that the letters should be reversed in order (I've seen 'passed up' mean this).
'plans' becomes 'maps' (I've seen this before).
'maps' in reverse letter order is 'SPAM'.
'for' is the link.
(Other definitions for spam that I've seen before include "Tinned meat - unwanted email" , "Spiced ham" , "Tinned meat made largely from pork" , "email messages" , "Send unsolicited mail" .)