Rodents get new form of meat (5)
I believe the answer is:
mince
'form of meat' is the definition.
(I know that mince is a type of meat)
'rodents get new' is the wordplay.
'rodents' becomes 'mice' (mouse is a kind of rodent).
'get' is an insertion indicator.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'mice' going around 'n' is 'MINCE'.
(Other definitions for mince that I've seen before include "Ingredient of 8 across" , "meat that's prepared" , "Diced meat" , "Shredded beef" , "Shred (meat)" .)