Totally all in? (5,4)
I believe the answer is:
every inch
'totally' is the definition.
(every inch means completely or totally)
'all in?' is the wordplay.
'all' becomes 'every' (similar in meaning).
'in?' becomes 'inch' ('inch' can be a synonym of 'in').
'every'+'inch'='EVERY INCH'
(Other definitions for every inch that I've seen before include "Entirely" , "Absolutely!" , "completely" , "Thoroughly" , "Wholly" .)