To correspond in every detail (7)
I believe the answer is:
totally
'to correspond in every detail' is the definition.
I can't tell whether this definition defines the answer.
'to correspond' is the wordplay.
'correspond' becomes 'tally' (synonyms).
'to'+'tally'='TOTALLY'
Can you help me to learn more?
(Other definitions for totally that I've seen before include "in every respect" , "Dead" , "Allowing no exception" , "to the nth degree" , "Absolutely" .)