Ram has to reject Tally (3,2)
I believe the answer is:
tot up
'tally' is the definition.
(synonyms)
'ram has to reject' is the wordplay.
'ram' becomes 'tup' (synonyms).
'has' is an insertion indicator.
'reject' is a reversal indicator.
'to' back-to-front is 'ot'.
'tup' going around 'ot' is 'TOT UP'.
(Other definitions for tot up that I've seen before include "Determine the sum of" , "Reckon" , "Summate" , "Add together (driving offences)" , "Add (some numbers)" .)