Mix the meat with it then (2,3,4)
I believe the answer is:
at the time
'then' is the definition.
(synonyms)
'mix the meat with it' is the wordplay.
'mix' indicates an anagram.
'with' says to put letters next to each other.
'the'+'meat'='themeat'
'themeat' after 'it' is 'itthemeat'.
'itthemeat' anagrammed gives 'AT THE TIME'.
(Other definitions for at the time that I've seen before include "In that period" , "In those days" .)