I agree with you, I see (4)
I believe the answer is:
yeah
'i agree' is the definition.
(I've seen this before)
'with you i see' is the wordplay.
'with' means one lot of letters go next to another.
'you' becomes 'ye' (historical version of 'you').
'i see' becomes 'ah' (exclamation used to indicate understanding).
'ye' next to 'ah' is 'YEAH'.
(Other definitions for yeah that I've seen before include "quite casually" , "Informal agreement" , "Certainly" , "Exclamation of agreement (or doubt!)" , "Surely" .)